JP2014056081A - Developing device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device capable of effectively suppressing hysteresis not only initially but over time, to provide high-quality full-color images; and an image forming apparatus.SOLUTION: A developing device includes a developer carrier that is arranged opposite to an electrostatic latent image carrier, and carries a developer to develop an electrostatic latent image formed on the electrostatic latent image carrier to convey the developer to a development area. The developer includes a toner containing toner base containing at least a binder resin and colorant, and an external additive; and a carrier. The toner contains, as the external additive, joined particles formed by a plurality of primary particles being joined to each other. The work function Wc of the carrier and the work function Ws of the developer carrier satisfy the relationship of the following formula (1).

Description

  The present invention relates to a developing device used for electrophotographic image formation such as a copying machine, electrostatic printing, facsimile, printer, electrostatic recording, and the like, and an image forming apparatus.

In electrophotographic image formation, an electrostatic charge image (latent image) is formed on an electrostatic latent image carrier, and the latent image is developed using charged toner to form a toner image. It is transferred onto a recording medium such as paper and fixed by a method such as heating to obtain an output image.
In recent years, an electrophotographic image forming apparatus has been used also in the field of commercial printing, so-called production printing, and there is a demand for an image forming apparatus capable of forming a full-color image with higher speed and higher image quality.

As one of the important issues in obtaining a high-quality full-color image, in order to faithfully reproduce the latent image on the electrostatic latent image carrier with toner, a toner amount corresponding to the desired image density is electrostatically applied. There is a problem of keeping it supplied on the latent image carrier.
For example, in the one-component development method, a phenomenon (fading phenomenon) has been reported that when the same image pattern is continuously output, a belt-like portion having a low image density occurs. This fading phenomenon is mainly caused by the fact that toner with a low charge amount is formed by a magnet in the developing sleeve and a blade (doctor blade) that regulates the toner layer thickness due to friction with the surface of the developer carrying member (developing sleeve). Occurs when the magnetic field passes through the magnetic field and is transported to the development area as a part of the toner layer and does not move onto the electrostatic latent image carrier even if it receives the development electric field. Therefore, in Patent Document 1 (Patent No. 3005081) and Patent Document 2 (Patent No. 3126433), the slope γ in work function measurement formed of a resin layer containing conductive fine particles or solid lubricant is 10. An image forming apparatus comprising: a developing sleeve having the surface layer as described above; and a toner whose weight average particle diameter, fine powder content, coarse powder content, and MI (melt index) value are controlled within a specific range; By using an image forming apparatus composed of a sleeve and a toner having an external additive treated with silicone oil or silicone varnish, the toner can be stably charged to a desired value even in a high temperature and high humidity environment. Regardless of the friction between the toner and the developing sleeve surface, only the toner with the appropriate charge amount is applied to the developing area by the mirror image force acting between the toner and the developing sleeve. So as to prevent the fading phenomenon by sending.

  Further, even in the two-component development method more suitable for the high speed of the image forming apparatus, it has been reported that when a developer is used for a long period of time, a development phenomenon is lowered and a hysteresis phenomenon occurs in which the image density decreases (for example, (See Patent Document 3). The hysteresis phenomenon in the two-component development method here is due to the fact that the two-component developer is not normally peeled off. The developer is peeled off by using an odd number of magnets in the developing sleeve and providing a pair of magnets with the same polarity below the rotation axis of the developing sleeve to create a peeling region where the magnetic force is almost zero. Is used to let the developer after development drop naturally. However, counter charge is generated in the carrier when the amount of toner consumed in the immediately preceding image is generated, so that a mirror image force is generated between the carrier and the developer carrying member, and the developer is not normally separated. For this reason, the developer whose toner concentration has decreased due to toner consumption is conveyed again to the development area, and the developing ability is reduced. That is, the image density is normal for one round of the sleeve, whereas the image density becomes thin after the second round. On the other hand, Patent Document 3 proposes a method in which a drawing roll having a magnet inside is arranged in the vicinity of a peeling region on the developing sleeve, and the developer after the development is peeled off with the magnetic force. The peeled developer is pumped up by another scooping roll and then conveyed to a developer stirring chamber having a screw, where toner density is readjusted and toner is charged. However, in the above proposal, the initial history phenomenon can be solved, but if the use is continued over time, the sufficient effect cannot be exhibited and the history phenomenon occurs. was there.

While the present inventors are studying an image forming apparatus capable of forming a full color image with high speed and high image quality, as another hysteresis phenomenon in the two-component development method, toner remaining without being developed in the development region Is not collected with the carrier, remains attached to the developer carrier, and remains on the developer carrier when transported again to the development area with the newly pumped developer during the next development. It has been found that there is a problem that an image density difference occurs depending on the presence or absence of toner. This history phenomenon is considered to occur when the adhesion force between the toner and the developer carrying member becomes larger than the adhesion force between the toner and the carrier. This tendency becomes prominent when the developer is continuously stirred over time under a condition where the toner consumption is small, and particularly, in the case of a high-speed machine. Further, in response to the recent demand for energy saving, toner is being fixed at low temperature. As one of the means, a crystalline resin (especially crystalline polyester) showing a sharp melting characteristic with respect to temperature in the toner. Many proposals have been made to add (resin), but in an image forming apparatus using such a low-temperature fixing toner, this hysteresis phenomenon tends to become more prominent.
It is an object of the present invention to provide a developing device that can effectively suppress such a hysteresis phenomenon not only initially but also over time and obtain a high-quality full-color image.

As a result of intensive studies in view of the above problems, the present inventors have developed a developer that develops an electrostatic latent image that is disposed opposite to the electrostatic latent image carrier and formed on the electrostatic latent image carrier. In a developing device including a developer carrying member that is carried and conveyed to a developing region, the developer includes a toner base containing at least a binder resin and a colorant, a toner containing an external additive, and a carrier And the external additive contains coalesced particles in which a plurality of primary particles are coalesced, and the work function Wc of the carrier and the work function Ws of the developer carrier are represented by the following formula (1): By satisfying this relationship, it was found that the hysteresis phenomenon can be effectively suppressed not only initially but also over time.

The present invention is based on the above findings by the present inventors, and specific means for solving the above problems are as follows. That is,
In a developing device provided with a developer carrying member disposed opposite to an electrostatic latent image carrying member and carrying a developer for developing the electrostatic latent image formed on the electrostatic latent image carrying member and transporting the developer to a development region. ,
The developer includes a toner base containing at least a binder resin and a colorant, a toner containing an external additive, and a carrier.
As the external additive, containing coalescing particles formed by coalescing a plurality of primary particles,
The developing device, wherein a work function Wc of the carrier and a work function Ws of the developer carrier satisfy the relationship of the following formula (1).

  According to the present invention, there is provided a developing device capable of effectively suppressing the hysteresis phenomenon in the two-component developing system not only initially but also over time and obtaining a high-quality full-color image.

FIG. 1 is a photograph showing an example of an external toner additive in the present invention. FIG. 2 is a photograph showing an example of the toner external additive in the present invention. FIG. 3 is a photograph showing an example of the toner external additive in the present invention. FIG. 4 is a photograph showing an example of an external additive in which the ratio of cracked or disintegrated particles in 1,000 coalesced particles is 30% or less. In the figure, the scale of the arrow indicates 300 nm. FIG. 5 is a photograph showing an example of an external additive in which the proportion of cracked or disintegrated particles in 1,000 coalesced particles exceeds 30%. In the figure, the scale of the arrow indicates 300 nm. FIG. 6 is a schematic explanatory view showing an example of the image forming apparatus of the present invention. FIG. 7 is a schematic explanatory view showing another example of the image forming apparatus of the present invention. FIG. 8 is a schematic explanatory view showing an example using the tandem color image forming apparatus of the image forming apparatus of the present invention. FIG. 9 is a partially enlarged schematic explanatory view of the image forming apparatus shown in FIG. FIG. 10 is a diagram illustrating an example of a normal image and an abnormal image in the vertical band chart.

  The toner, carrier, and developer carrying member constituting the developing device of the present invention will be described. Note that it is easy for a person skilled in the art to change or modify the present invention within the scope of the claims to form other embodiments, and these changes and modifications are included in the scope of the claims, The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

(Developer)
The developing device of the present invention includes at least a developer composed of toner and a carrier, and a developer carrier.

The developing device of the present invention is characterized in that the work function Wc of the carrier and the work function Ws of the developer carrier satisfy the relationship of the following formula (1).
The occurrence of the hysteresis phenomenon in the two-component development system, which is a problem in the present invention, is considered to be related to the adhesion force Ftsc between the toner and the carrier and the adhesion force Fts between the toner and the developer carrier. When the toner becomes larger than Ftc, the toner that remains undeveloped in the development area is not normally held by the carrier, remains on the developer carrier, and is newly pumped as it is in the next development. When the toner is conveyed again to the development area together with the developer, it is considered that an image density difference occurs depending on the presence or absence of residual toner on the developer carrying member, and appears as a hysteresis phenomenon. In the above formula (1), Wc is related to the electrostatic adhesive force between the toner and the carrier, and Ws is related to the electrostatic adhesive force between the toner and the developer carrying member. Wc contributes to the value of the charge amount when the toner and the carrier are frictionally charged, and the value becomes smaller, thereby increasing the charge amount of the toner due to frictional charging and electrostatically between the toner and the carrier. There is a tendency that the adhesion force is increased and the toner is easily held on the carrier normally. On the other hand, regarding Ws, it is considered that the charged toner held on the carrier contributes to the charge transfer between the toner and the developer carrier when contacting the developer carrier, and the value becomes larger. In the vicinity of the contact point between the charged toner and the developer carrier, the amount of charge transfer from the toner to the developer carrier increases, and the electrostatic adhesion between the toner and the developer carrier tends to be reduced. When these relationships satisfy the relationship of the above formula (1), the adhesion force between the toner and the carrier becomes larger than the adhesion force between the toner and the developer carrying member, and the occurrence of a hysteresis phenomenon can be suppressed. .

  The work function Wc of the carrier and the work function Ws of the developer carrier can be measured using, for example, a work function measuring device (a surface analyzer AC-2 manufactured by Riken Keiki Co., Ltd.) using a photoelectric effect. it can. Specifically, a carrier is put into a concave portion of a sample measuring cell (having a shape having a concave portion having a diameter of 10 mm and a depth of 1 mm in the center of a stainless steel disk having a diameter of 13 mm and a height of 5 mm), and a knife edge is used. Level the surface. After the sample measurement cell filled with the carrier is fixed on the specified position of the sample stage, the irradiation light quantity is set to 500 nW, the irradiation area is set to 4 mm square, and the measurement is performed under the conditions of the energy scanning range of 3.4 to 6.2 eV.

(Developer carrier)
The developer carrier of the present invention is not particularly limited as long as it satisfies the relationship of the formula (1), and various conventionally known developer carriers can be used. The work function Ws of the developer carrier in the above formula (1) is determined by the surface material constituting the developer carrier, and examples of the material constituting the developer carrier include Al (Ws: 3.7 eV). SUS (Ws: 4.4 eV), TiN (Ws: 4.7 eV), or the like can be used.

(toner)
The toner of the present invention contains a toner base and an external additive, and further contains other components as necessary.

<External additive>
The external additive is not particularly limited as long as it contains coalesced particles formed by coalescing a plurality of primary particles, and can be appropriately selected according to the purpose.
By controlling the particle size distribution of the coalesced particles as an external additive, and the crackability within the following specific range, the coalesced particles on the toner surface can be retained without being embedded or detached even with agitation stress over time, An increase in non-electrostatic adhesion between the toner and the developer carrying member is suppressed, and the occurrence of a hysteresis phenomenon can be suppressed over time even in a high-speed toner machine.

<< coalescence particles >>
The coalesced particles are non-spherical particles in which a plurality of primary particles are coalesced, that is, as shown in FIG. It is a particle having a coalesced portion, which is different from a state where primary particles are simply aggregated while maintaining their shape. The “cohesive particles” may be referred to as “secondary particles”.

-Primary particles-
The primary particles are not particularly limited and can be appropriately selected depending on the purpose. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, Tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, etc. Inorganic fine particles, organic fine particles, and the like. These may be used alone or in combination of two or more. Among these, silica is preferable in that it can prevent the external additive from being buried and detached from the toner base particles.

  There is no restriction | limiting in particular as average particle diameter (Da) of the said primary particle, Although it can select suitably according to the objective, 20 nm-150 nm are preferable and 35 nm-150 nm are more preferable. When the average particle size of the primary particles is less than 20 nm, the embedding of the external additive in the toner base due to external stress cannot be sufficiently suppressed, and the function as a spacer cannot be exhibited. There is a case where a non-electrostatic adhesion force between the bodies increases and a hysteresis phenomenon is likely to occur, which is not preferable. On the other hand, if the thickness exceeds 150 nm, the toner is likely to be liberated and the filming of the photoconductor is likely to occur, which is not preferable.

  The average particle diameter (Da) of the primary particles was measured based on the particle diameter of primary particles in the coalesced particles (the length of all arrows shown in FIG. 1). In the measurement, a sample obtained by dispersing the secondary particles in an appropriate solvent (such as THF) and then removing the solvent on a substrate to dry the sample was measured using a field emission scanning electron microscope (FE-SEM, acceleration). (Voltage: 5 kV to 8 kV, observation magnification: 8,000 to 10,000 times), and measuring the particle diameter of primary particles in the visual field. The primary particle size is measured by predicting the entire image from the outer frame of the coalesced particles and measuring the average value of the longest length of all images (the length of all arrows shown in FIG. 1). Number: 100 or more and 200 or less).

-Secondary particles-
The secondary particles are not particularly limited and may be appropriately selected depending on the purpose. However, as shown by reference numeral 1 in FIG. 3, particles (secondary particles obtained by chemically bonding the primary particles with a treating agent described later) (Secondary agglomerated particles) are preferable, and particles obtained by chemically bonding the primary particles by a sol-gel method are more preferable. Specific examples include sol-gel silica.

  The average particle diameter (Dba) of the secondary particles, that is, the number average particle diameter of the coalesced particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 80 nm to 200 nm, preferably 100 nm to 180 nm is more preferable, and 100 nm to 160 nm is particularly preferable. When the number average particle diameter is less than 80 nm, the embedding of the external additive in the toner base due to external stress cannot be sufficiently suppressed, and as a result, the function as a spacer cannot be exhibited. This is not preferable because the non-electrostatic adhesion force may increase and a hysteresis phenomenon is likely to occur. On the other hand, if it exceeds 200 nm, release from the toner is likely to occur, and photoconductor filming is likely to occur, which is not preferable.

  The number average particle size (Dba) of the secondary particles is measured by dispersing the secondary particles in a suitable solvent (tetrahydrofuran (THF) or the like) and then removing the solvent on the substrate to dry the sample. By measuring the particle diameter of secondary particles in the field of view with a field emission scanning electron microscope (FE-SEM, acceleration voltage: 5 kV to 8 kV, observation magnification: 8,000 times to 10,000 times). Specifically, the entire image is predicted from the outer frame of the secondary particles that are attached, and the longest length of the entire image (the length of the arrow shown in FIG. 2) is measured (number of particles measured: 100 ) Or more.

-Manufacturing method of coalesced particles-
The method for producing the coalesced particles is not particularly limited and may be appropriately selected depending on the intended purpose. However, a method of producing by the sol-gel method is preferable, and specifically, the primary particles and the treatment agent are mixed. Or the method of manufacturing by carrying out the chemical bonding by baking and making it secondary-aggregate and making it secondary particle | grains (fusion particle | grains) is preferable. When synthesizing by the sol-gel method, coalescent particles may be prepared by a one-step reaction in the presence of the treatment agent. Although an example of a manufacture example is shown below, it is not restricted to this.

-Treatment agent-
There is no restriction | limiting in particular as said processing agent, According to the objective, it can select suitably, For example, a silane processing agent, an epoxy processing agent, etc. are mentioned. These may be used alone or in combination of two or more. When silica is used as the primary particles, the Si—O—Si bond formed by the silane-based treatment agent is more heated than the Si—O—C bond formed by the epoxy-based treatment agent. From the viewpoint of stability, a silane-based treatment agent is preferable. Moreover, you may use processing adjuvants (water, 1 mass% acetic acid aqueous solution, etc.) as needed.

--- Silane treatment agent ---
There is no restriction | limiting in particular as said silane type processing agent, According to the objective, it can select suitably, For example, alkoxysilanes (tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxy) Silane, dimethyldiethoxysilane, methyldimethoxysilane, methyldiethoxysilane, diphenyldimethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, etc.); silane coupling agents (γ-aminopropyltolethoxysilane, γ-glycidoxy) Propyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, vinyltriethoxysilane, methylvinyldi Methoxysilane, etc.); vinyltrichlorosilane, dimethyldichlorosilane, methylvinyldichlorosilane, methylphenyldichlorosilane, phenyltrichlorosilane, N, N′-bis (trimethylsilyl) urea, N, O-bis (trimethylsilyl) acetamide, dimethyltrimethylsilyl Examples thereof include a mixture of amine, hexamethyldisilazane and cyclic silazane.

The silane-based treatment agent forms secondary agglomeration by chemically bonding the primary particles (for example, silica primary particles) as described below.
When the silica primary particles are treated using the alkoxysilanes, the silane coupling agent, or the like as the silane treatment agent, as shown in the following formula (A), a silanol group bonded to the silica primary particles And an alkoxy group bonded to the silane-based treatment agent react to form a new Si—O—Si bond by dealcoholization and secondary aggregation.
When the silica primary particles are treated with the chlorosilanes as the silane-based treatment agent, the chloro group of the chlorosilanes and the silanol group bonded to the silica primary particles are dehydrochlorinated to form new Si. The silanol group bonded to —O—Si forms a new Si—O—Si bond by the dehydration reaction, and secondarily aggregates. Further, when the silica primary particles are treated with the chlorosilanes as the silane-based treatment agent, when water coexists in the system, the chlorosilanes are first hydrolyzed into water to generate silanol groups, The silanol groups bonded to the silanol groups and the silica primary particles form a new Si—O—Si bond by the dehydration reaction, and are secondarily aggregated.
When the silica primary particles are treated with silazanes as the silane treatment agent, a new Si-O-Si bond is formed by deammoniation of the silanol groups bonded to the amino groups and the silica primary particles. Secondary aggregation.
However, in said formula (A), R shows an alkyl group.

--- Epoxy-based treatment agent ---
The epoxy-based treatment agent is not particularly limited and may be appropriately selected depending on the purpose. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, Examples thereof include bisphenol A novolac type epoxy resin, biphenol type epoxy resin, glycidylamine type epoxy resin, and alicyclic epoxy resin.

As shown in the following formula (B), the epoxy treating agent chemically bonds the silica primary particles to form secondary aggregation. When the silica primary particles are treated using the epoxy-based treatment agent, silanol groups bonded to the silica primary particles add an epoxy group oxygen atom and a carbon atom bonded to the epoxy group of the epoxy-based treatment agent. Thus, a new Si—O—C bond is formed and secondary aggregation occurs.

  There is no restriction | limiting in particular as mixing mass ratio (primary particle: treatment agent) of the said processing agent and the said primary particle, Although it can select suitably according to the objective, 100: 0.01-100: 50 is preferable. . In addition, there exists a tendency for a coalescence degree to become high, so that there is much quantity of the said processing agent.

  There is no restriction | limiting in particular as a mixing method of the said processing agent and the said primary particle, According to the objective, it can select suitably, For example, the method of mixing with a well-known mixer (spray dryer etc.) etc. are mentioned. When mixing, the primary particles may be prepared and then mixed with the treatment agent, or when the primary particles are prepared, the treatment agent is allowed to coexist and prepared in a one-step reaction. May be.

  There is no restriction | limiting in particular as baking temperature of the said processing agent and the said primary particle, Although it can select suitably according to the objective, 100 to 2500 degreeC is preferable. In addition, it exists in the tendency for a coalescence degree to become high, so that the said baking temperature is high.

  There is no restriction | limiting in particular as baking time of the said processing agent and the said primary particle, Although it can select suitably according to the objective, 0.5 to 30 hours are preferable.

-Particle size distribution index of coalesced particles-
By using particles satisfying the following formula (2) as the particle size distribution index of the coalesced particles, the particle size distribution of the coalesced particles becomes sharp. This increases the proportion of particles that function as spacers without being embedded in the toner matrix due to external stress, and more effectively suppresses the increase in non-electrostatic adhesion between the toner and developer carrier. Thus, the occurrence of a history phenomenon can be suppressed.
However, in the formula (2), Db ₅₀ is the coalesced particles when the particle size (nm) of the coalesced particles is on the horizontal axis and the cumulative value (number%) of the coalesced particles is on the vertical axis. Represents the particle size of the coalesced particles having a cumulative value of 50% by number when drawn from the small particle side, and Db ₁₀ represents the particle size of the coalesced particles having the cumulative value of 10% by number. Represents particle size.

The Db ₅₀ is represented, for example, by the cumulative distribution of the coalesced particles when the horizontal axis is the particle size (nm) of the coalesced particles and the cumulative value (number%) of the coalesced particles is the vertical axis. If the measured number of the coalesced particles is 200, the particle size of the 100th particle, and if it is 150, the particle size of the 75th coalesced particle.

The Db ₅₀ is measured by dispersing the coalesced particles in a suitable solvent (tetrahydrofuran (THF) or the like), and then removing the solvent on the substrate to dry the sample, using a field emission scanning electron microscope (FE-SEM, acceleration voltage: 5 kV to 8 kV, observation magnification: 8,000 times to 10,000 times) The particle size of coalesced particles in the visual field is measured, and the cumulative value becomes 50%. This is done by measuring the particle size of the coalesced particles. The particle size of the coalesced particles is measured by measuring the longest length of aggregated particles (the length of the arrow shown in FIG. 2) (measured number of particles: 100 or more and 200 or less).

The Db ₁₀ is represented, for example, by the cumulative distribution of the coalesced particles when the horizontal axis is the particle size (nm) of the coalesced particles and the cumulative value (number%) of the coalesced particles is the vertical axis. When the measured number of the coalesced particles is 200, the particle size of the 20th coalesced particle is the 20th particle, and when it is 150, the particle size of the 15th coalesced particle is used.

The measurement of the Db _{10 in} the coalesced particles is performed by measuring the electric field radiation of a sample obtained by dispersing the coalesced particles in an appropriate solvent (tetrahydrofuran (THF) or the like) and then removing the solvent on the substrate to dry it. The particle diameter of coalesced particles in the field of view is measured with a scanning electron microscope (FE-SEM, acceleration voltage: 5 kV to 8 kV, observation magnification: 8,000 times to 10,000 times). The measurement is carried out by measuring the particle size of the coalesced particles to be 10%. The particle size of the coalesced particles is measured by measuring the longest length of aggregated particles (the length of the arrow shown in FIG. 2) (measured number of particles: 100 or more and 200 or less).

The “Db ₅₀ / Db ₁₀ ” is preferably 1.2 or less, and more preferably 1.15 or less. When the “Db ₅₀ / Db ₁₀ ” exceeds 1.2, the particle size distribution of the coalesced particles is wide and the number of particles having a small particle size increases. That is, “small particle A” (particles that are not coalesced and exist in the form of primary particles) or “small particle B” (coagulant is advancing, but primary particles This means that at least one of the particles having a small particle size is large. When the “small particle A” is large, the function as a non-spherical external additive cannot be achieved, and the embedding resistance is poor. Increase in adhesive force cannot be suppressed, and a hysteresis phenomenon may occur easily. On the other hand, if the “small particle B” is large, the function as a spacer cannot be achieved, so that an increase in non-electrostatic adhesion between the toner and the developer carrying member cannot be suppressed. In addition, a history phenomenon is likely to occur, which is not preferable. Therefore, it is necessary to reduce the “small particle A” and the “small particle B”.

  The method for reducing the “small particle A” and the “small particle B” is not particularly limited and may be appropriately selected depending on the intended purpose. A method of removing particles having a diameter is preferable.

-Crack resistance of coalesced particles-
The coalescing particles preferably satisfy the following formula (3), and more preferably satisfy the following formula (3-1). As a result, the cohesive force (cohesion force) between the primary particles constituting the coalesced particles is maintained even with agitation stress in the developing machine, so that the toner-development can be more effectively performed without being embedded in the toner base. It is possible to suppress an increase in non-electrostatic adhesion force between the agent-carrying members and suppress the occurrence of a hysteresis phenomenon not only in the initial stage but also over time.
However, in the above formulas (3) and (3-1), Nx represents the number of cracked or disintegrated particles in the 1,000 coalesced particles. The number of cracked or disintegrated particles in the 1,000 particles is about a rocking mill (67 Hz, 10 minutes) for 0.5 g of the coalesced particles and 49.5 g of the carrier in a 50 mL bottle. The product is agitated using Seiwa Giken Co., Ltd. and then observed and selected with a scanning electron microscope.

  When the cohesive force of the coalesced particles is strong (as shown in FIG. 4), the ratio of cracked or disintegrated particles (for example, particles shown in a black frame in FIG. 4) in the 1,000 coalesced particles is (When it is 30% or less), the external additive in the toner has less particles (cracking or collapsing particles) that cause cracking or disintegration due to the load of the developing device, etc., and the embedding and rolling of the external additive are suppressed. This is preferable because the occurrence of a hysteresis phenomenon can be suppressed.

  When the cohesive force of the coalesced particles is weak (as shown in FIG. 5), the ratio of cracked or disintegrated particles (for example, particles shown in a black frame in FIG. 5) in 1,000 of the coalesced particles is (When it exceeds 30%), the number of particles in which the external additive in the toner is cracked or disintegrated by a load such as a developing device increases, the ratio of spherical particles increases, and the external additive tends to move or be buried. This is not preferable because the occurrence of a history phenomenon over time may not be suppressed.

-Condition (3)-
In the formula (3), the cracked or disintegrated particles refer to particles that are present alone as the primary particles. And particles that have been present as primary particles alone before the stirring, for example, particles 2 shown in FIG. 3 and black particles shown in FIGS. Thus, the particle | grains etc. which the particle | grains exist independently, without the said primary particle being united are mentioned.
In the formula (3), the shape of the cracked or disintegrated particles is not particularly limited as long as the particles are not bonded to each other, and can be appropriately selected according to the purpose. As indicated by reference numeral 2, it is often present in a substantially spherical state.

In the formula (3), the method for confirming the presence of the cracked or disintegrated particles is not particularly limited and may be appropriately selected depending on the intended purpose. However, with a scanning electron microscope (SEM) A method of confirming the existence of particles alone by observing is preferable.
The method for measuring the average particle size of the cracked or disintegrated particles is not particularly limited and may be appropriately selected depending on the intended purpose. However, a scanning electron microscope (FE-SEM, acceleration voltage: 5 kV to 8 kV, observation magnification: (8,000 times to 10,000 times) by measuring the average value of the diameters of the cracked or disintegrated particles in the field of view (measured number of particles: 100 or more).

In the above formula (3), as the measurement of cracks or disintegrated particles in 1,000 particles, after stirring, the particles are observed with a scanning electron microscope, and reference numeral 2 in FIG. 3 and black frames in FIGS. As in the case of the particles shown in the figure, the particles existing alone are measured as one cracked or disintegrated particle.
In the above formula (3), when measuring the number of cracked or disintegrated particles in 1,000 particles, coalescence particles formed by coalescing a plurality of particles were confirmed by the scanning electron microscope. In this case, the coalesced particles are measured as one particle.

The carrier used in the formula (3) is a resin obtained by applying or drying a coating film forming solution of an acrylic resin and a silicone resin containing alumina particles on the surface of a fired ferrite powder (weight average particle diameter: 35 μm). Use a coated ferrite carrier.
In said Formula (3), there is no restriction | limiting in particular as said 50 mL bottle, According to the objective, it can select suitably, For example, the commercially available glass bottle (made by Nidec Rika Glass Co., Ltd.) etc. are mentioned.

-Characteristics of coalesced particles-
The degree of coalescence is determined by measuring the primary particle diameter and the secondary particle diameter of the coalesced particles. The secondary particle diameter of one coalesced particle and the primary particles of a plurality of primary particles constituting the coalesced particle The average value of the diameters is obtained and obtained by the following formula.
Degree of coalescence = secondary particle diameter / average primary particle diameter Observe about 100 or more coalesced particles, determine the degree of coalescence of each particle, the average value of the degree of coalescence, and the degree of coalescence is 1.3. Find the ratio less than.
There is no restriction | limiting in particular as an average of the coalescence degree of the said coalesced particle, Although it can select suitably according to the objective, 1.5-4.0 are preferable. When the average degree of coalescence is less than 1.5, the function as a non-spherical external additive cannot be achieved, and the coalesced particles are easily transferred to the recesses on the surface of the toner base. -It is not preferable because an increase in non-electrostatic adhesion between developer carriers cannot be sufficiently suppressed, and a hysteresis phenomenon is likely to occur. On the other hand, if it exceeds 4.0, the coalesced particles are easily peeled off from the toner base, and the carrier contamination and the photoconductor may be damaged, which may cause image defects over time, which is not preferable.

  The content of the coalesced particles having a coalescence degree of less than 1.3 in the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10% by number or less. The degree of coalescence has a distribution in production, and the particles having the degree of coalescence of less than 1.3 are particles in which the coalescence has not progressed and are present in a nearly spherical state. . Therefore, it is difficult to perform the function as a non-spherical additive characterized for suppressing burial. The content of the coalesced particles having a coalescence degree of less than 1.3 is measured by the above-described method using the average primary particle size of the coalesced particles and the particle size of the secondary particles as 100. After measuring from 200 to 200, the degree of coalescence of each coalesced particle is calculated from the obtained measurement value, and the number of particles with the degree of coalescence less than 1.3 is divided by the number of measurements. .

  The method for confirming that the primary particles of the coalesced particles are coalesced is not particularly limited and can be appropriately selected according to the purpose, but is observed with a scanning electron microscope (SEM). Thus, a method of confirming that the primary particles are coalesced is preferable.

  There is no restriction | limiting in particular as content of the said external additive, Although it can select suitably according to the objective, 0.5 mass part-4.0 mass parts are preferable with respect to 100 mass parts of toner base particles. .

-Other external additives-
In addition to the coalesced particles, various external additives can be added to the toner for the purpose of fluidity modification, charge amount adjustment, and electrical property adjustment. The external additive is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, silica fine particles, hydrophobized silica fine particles, fatty acid metal salts (for example, zinc stearate, stearin) Metal oxides (for example, titania, alumina, tin oxide, antimony oxide, etc.) or their hydrophobized products, fluoropolymers, and the like. Among these, hydrophobized silica fine particles, titania particles, and hydrophobized titania fine particles are preferable.
The content of other external additives is not particularly limited and may be appropriately selected depending on the intended purpose, but is 0.3 parts by mass to 3.0 parts by mass with respect to 100 parts by mass of the toner base particles. preferable.

  Examples of the hydrophobized silica fine particles include HDK H2000, HDK H2000 / 4, HDK H2050EP, HVK21, HDK H1303 (all manufactured by Hoechst); R972, R974, RX200, RY200, R202, R805, R812 (all Also manufactured by Nippon Aerosil Co., Ltd.). Examples of the titania fine particles include P-25 (manufactured by Nippon Aerosil Co., Ltd.); STT-30, STT-65C-S (both manufactured by Titanium Industry Co., Ltd.); TAF-140 (manufactured by Fuji Titanium Industry Co., Ltd.); Examples include MT-150W, MT-500B, MT-600B, MT-150A (all manufactured by Teika Corporation). Examples of the hydrophobized titanium oxide fine particles include T-805 (manufactured by Nippon Aerosil Co., Ltd.); STT-30A, STT-65S-S (both manufactured by Titanium Industry Co., Ltd.); TAF-500T, TAF-1500T. (Both manufactured by Fuji Titanium Industry Co., Ltd.); MT-100S, MT-100T (both manufactured by Teika Co., Ltd.); IT-S (produced by Ishihara Sangyo Co., Ltd.) and the like.

<Toner base particles>
The toner base particles contain at least a binder resin and a colorant. Furthermore, a mold release agent, a charge control agent, a layered inorganic mineral, etc. can be contained as needed.

<< Binder resin >>
The binder resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polyester resin, silicone resin, styrene / acryl resin, styrene resin, acrylic resin, epoxy resin, diene resin, phenol Resins, terpene resins, coumarin resins, amideimide resins, butyral resins, urethane resins, ethylene vinyl acetate resins and the like can be mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, polyester resin, polyester resin and the above-mentioned other binder resins are combined in that they have excellent low-temperature fixability, can smooth the image surface, and have sufficient flexibility even when the molecular weight is lowered. Resins are preferred.

-Polyester resin-
There is no restriction | limiting in particular as said polyester resin, Although it can select suitably according to the objective, An unmodified polyester resin and a modified polyester resin are preferable. These may be used individually by 1 type and may use 2 or more types together.

--Unmodified polyester resin--
There is no restriction | limiting in particular as said unmodified polyester resin, According to the objective, it can select suitably, For example, the polyol represented by following General formula (1), and poly represented by following General formula (2) Examples thereof include resins obtained by polyesterifying carboxylic acid and crystalline polyester resins. According to the present invention, in a high-speed machine equipped with a toner having excellent low-temperature fixability using a crystalline polyester resin, in which the hysteresis phenomenon becomes more prominent, a developing device that can similarly suppress the occurrence of the hysteresis phenomenon over time, An image forming apparatus can be provided.
However, in the said General formula (1), A represents the aromatic group or heterocyclic aromatic group which may have a C1-C20 alkyl group, an alkylene group, and a substituent, m is 2- Represents an integer of 4.
However, in said general formula (2), B represents the C1-C20 alkyl group, alkylene group, the aromatic group which may have a substituent, or a heterocyclic aromatic group, and n is 2-2. Represents an integer of 4.

  There is no restriction | limiting in particular as a polyol represented by the said General formula (1), According to the objective, it can select suitably, For example, ethylene glycol, diethylene glycol, triethylene glycol, 1, 2- propylene glycol, 1, 3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene Glycol, polypropylene glycol, polytetramethylene glycol, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, bisphenol A, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, hydrogenated bisphenol A, hydrogenated bisphenol A ethylene oxide adduct, hydrogenated bisphenol A propylene oxide adduct, and the like. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as polycarboxylic acid represented by the said General formula (2), According to the objective, it can select suitably, For example, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalate Acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, isooctyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid , N-octenyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid, 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-di Ruboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empor trimer Examples include acids, etc., cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, butanetetracarboxylic acid, diphenylsulfonetetracarboxylic acid, ethylene glycol bis (trimellitic acid), and the like. These may be used alone or in combination of two or more.

--- Crystalline polyester resin ---
A crystalline polyester resin can be contained as the polyester resin.
Examples of the crystalline polyester resin include saturated aliphatic diol compounds having 2 to 12 carbon atoms as alcohol components, particularly 1,4-butanediol, 1,6-hexanediol, 1, -8 octanediol, 1,10- Decanediol, 1,12 dodecanediol, and derivatives thereof, and a dicarboxylic acid having 2 to 12 carbon atoms having at least a double bond (C═C bond) as an acidic component, or a saturated dicarboxylic acid having 2 to 12 carbon atoms, Especially synthesized using fumaric acid, 1,4-butanedioic acid, 1,6-hexanedioic acid, 1, -8 octanedioic acid, 1,10-decanedioic acid, 1,12 dodecanedioic acid and their derivatives. Preferred are crystalline polyesters.

  Among them, in particular, 1,4-butanediol, 1,6-hexanediol, 1, -8 octanediol, 1,10-decanediol, 1,12 in that the difference between the endothermic peak temperature and the endothermic shoulder temperature is further reduced. Any one kind of alcohol component of dodecanediol, fumaric acid, 1,4-butanedioic acid, 1,6-hexanedioic acid, 1, -8 octanedioic acid, 1,10-decanedioic acid, 1,12 -It is preferably composed of only one kind of dicarboxylic acid component of dodecanedioic acid.

  In addition, as a method for controlling the crystallinity and softening point of the crystalline polyester resin, a trivalent or higher polyhydric alcohol such as glycerin as an alcohol component and a trivalent or higher polyvalent such as trimellitic anhydride as an acid component can be used during polyester synthesis. Examples thereof include a method of designing and using a non-linear polyester that has been subjected to condensation polymerization by adding a polyvalent carboxylic acid.

  The molecular structure of the crystalline polyester resin of the present invention can be confirmed by X-ray diffraction, GC / MS, LC / MS, IR measurement, etc. in addition to NMR measurement by solution or solid.

  The content of the crystalline polyester resin in the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 3% by weight to 15% by weight, and more preferably 5% by weight to 10% by weight. preferable. When the content is less than 3% by weight, the effect on the low-temperature fixability may not be sufficiently obtained, which is not preferable. When the content exceeds 15% by mass, the image density stability over time, particularly in a high-speed machine, is not preferable. This is not preferable because the image density stability over time tends to deteriorate.

--Modified polyester resin--
There is no restriction | limiting in particular as said modified polyester resin, According to the objective, it can select suitably, For example, polyester (henceforth "polyester prepolymer" which can react with an active hydrogen group containing compound and the said active hydrogen group containing compound) And a resin obtained by an extension reaction and / or a crosslinking reaction. The extension reaction and / or the cross-linking reaction may be stopped by a reaction terminator (blocked monoamine such as diethylamine, dibutylamine, butylamine, laurylamine, ketimine compound, etc.) as necessary.

--- Active hydrogen group-containing compound ---
The active hydrogen group-containing compound acts as an elongation agent, a crosslinking agent or the like when the polyester prepolymer undergoes an elongation reaction, a crosslinking reaction, or the like in an aqueous phase.

  The active hydrogen group-containing compound is not particularly limited as long as it has an active hydrogen group, and can be appropriately selected according to the purpose. However, when the polyester prepolymer is an isocyanate group-containing polyester prepolymer described later. An amine is preferable in that a high molecular weight can be obtained.

  There is no restriction | limiting in particular as said active hydrogen group, According to the objective, it can select suitably, For example, a hydroxyl group (alcoholic hydroxyl group or phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group etc. are mentioned. These may be contained singly or in combination of two or more.

  The amines that are the active hydrogen group-containing compounds are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include diamines, trivalent or higher polyamines, amino alcohols, amino mercaptans, amino acids, and the like. The thing etc. which blocked the amino group of amines are mentioned. Examples of the diamine include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, Isophorone diamine, etc.); aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyamine include diethylenetriamine and triethylenetetramine. Examples of the amino alcohol include ethanolamine and hydroxyethylaniline. Examples of the amino mercaptan include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid include aminopropionic acid and aminocaproic acid. Examples of the blocked amino groups of these amines include, for example, any of these amines (diamine, trivalent or higher polyamine, amino alcohol, amino mercaptan, amino acid, etc.) and ketones (acetone, methyl ethyl ketone, And ketimine compounds and oxazolyzone compounds obtained from methyl isobutyl ketone and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, the amines are particularly preferably diamine and a mixture of a diamine and a small amount of a trivalent or higher polyamine.

--- Polymer capable of reacting with active hydrogen group-containing compound ---
The polymer capable of reacting with the active hydrogen group-containing compound is not particularly limited as long as it is a polymer having at least a group capable of reacting with the active hydrogen group-containing compound, and can be appropriately selected according to the purpose. However, it has excellent fluidity and transparency when melted, it is easy to adjust the molecular weight of the polymer component, and it is excellent in oilless low-temperature fixability and releasability in dry toners. ) Is preferred, and an isocyanate group-containing polyester prepolymer is more preferred.

  The isocyanate group-containing polyester prepolymer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a polycondensate of a polyol and a polycarboxylic acid, a reactive hydrogen group-containing polyester resin is reacted with a polyisocyanate. And the like.

  The polyol is not particularly limited and may be appropriately selected depending on the intended purpose. For example, alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.), alkylene ether glycol (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.), alicyclic diol (1,4-cyclohexanedimethanol, Hydrogenated bisphenol A, etc.), bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.), alkylene oxides of the above alicyclic diols (ethylene oxide, propylene oxide) Diol, butylene oxide etc.) adducts, diols such as alkylene oxide (ethylene oxide, propylene oxide, butylene oxide etc.) adducts of the above bisphenols; polyhydric aliphatic alcohols (glycerin, trimethylol ethane, trimethylol propane, pentaerythritol) , Sorbitol, etc.) Trivalent or higher valent phenols (phenol novolak, cresol novolak, etc.), Trivalent or higher polyols such as alkylene oxide adducts of trihydric or higher polyphenols; Mixtures of diols and trivalent or higher polyols; Etc. These may be used individually by 1 type and may use 2 or more types together. Among these, the polyol is preferably the diol alone or a mixture of the diol and a small amount of the trivalent or higher polyol. Examples of the diol include alkylene glycols having 2 to 12 carbon atoms, alkylene oxide adducts of bisphenols (bisphenol A ethylene oxide 2 mol adduct, bisphenol A propylene oxide 2 mol adduct, bisphenol A propylene oxide 3 mol adduct, etc.) Is preferred.

  There is no restriction | limiting in particular as content in the isocyanate group containing polyester prepolymer of the said polyol, Although it can select suitably according to the objective, For example, 0.5 mass%-40 mass% are preferable, and 1 mass%- 30 mass% is more preferable, and 2 mass%-20 mass% is especially preferable. When the content is less than 0.5% by mass, the hot offset resistance is deteriorated, and it may be difficult to achieve both the storage stability of the toner and the low-temperature fixability. Fixability may deteriorate.

  There is no restriction | limiting in particular as said polycarboxylic acid, According to the objective, it can select suitably, For example, alkylene dicarboxylic acid (succinic acid, adipic acid, sebacic acid, etc.); Alkenylene dicarboxylic acid (maleic acid, fumaric acid, etc.) ); Aromatic dicarboxylic acid (terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, etc.); trivalent or higher polycarboxylic acid (trimellitic acid, pyromellitic acid, etc., C9-20 aromatic polycarboxylic acid, etc.), etc. Is mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, the polycarboxylic acid is preferably an alkenylene dicarboxylic acid having 4 to 20 carbon atoms and an aromatic dicarboxylic acid having 8 to 20 carbon atoms. In place of the polycarboxylic acid, an anhydride of polycarboxylic acid, a lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) may be used.

  The mixing ratio of the polyol and the polycarboxylic acid is not particularly limited and may be appropriately selected depending on the intended purpose. The mixing ratio of the hydroxyl group [OH] of the polyol and the carboxyl group [COOH] of the polycarboxylic acid is not limited. The equivalent ratio [OH] / [COOH] is preferably 2/1 to 1/1, more preferably 1.5 / 1 to 1/1, and particularly preferably 1.3 / 1 to 1.02 / 1.

  The polyisocyanate is not particularly limited and may be appropriately selected depending on the intended purpose. For example, aliphatic polyisocyanate (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, octamethylene Diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, tetramethylhexane diisocyanate, etc .; alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic diisocyanates (tolylene diisocyanate, diphenylmethane) Diisocyanate, 1,5-naphthylene diisocyanate, diphenylene-4, '-Diisocyanate, 4,4'-diisocyanato-3,3'-dimethyldiphenyl, 3-methyldiphenylmethane-4,4'-diisocyanate, diphenyl ether-4,4'-diisocyanate, etc .; araliphatic diisocyanate (α, α , Α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates (tris-isocyanatoalkyl-isocyanurate, triisocyanatocycloalkyl-isocyanurate, etc.); these phenol derivatives; blocked with oximes, caprolactam, etc. And the like. These may be used alone or in combination of two or more.

  The mixing ratio of the polyisocyanate and the active hydrogen group-containing polyester resin (hydroxyl group-containing polyester resin) is not particularly limited and may be appropriately selected depending on the intended purpose. ] And the equivalent ratio [NCO] / [OH] of hydroxyl group [OH] of the hydroxyl group-containing polyester resin is preferably 5/1 to 1/1, more preferably 4/1 to 1.2 / 1, and 3 / 1-1.5 / 1 is particularly preferred. When the equivalent ratio [NCO] / [OH] is less than 1/1, the offset resistance may be deteriorated, and when it exceeds 5/1, the low-temperature fixability may be deteriorated.

  There is no restriction | limiting in particular as content of the said polyisocyanate in the said isocyanate group containing polyester prepolymer, Although it can select suitably according to the objective, 0.5 mass%-40 mass% are preferable, and 1 mass% -30% by mass is more preferable, and 2% by mass to 20% by mass is particularly preferable. When the content is less than 0.5% by mass, the hot offset resistance is deteriorated, and it may be difficult to achieve both storage stability and low-temperature fixability. May get worse.

  The average number of isocyanate groups contained in one molecule of the isocyanate group-containing polyester prepolymer is preferably 1 or more, more preferably 1.2 to 5, and more preferably 1.5 to 4. When the average number is less than 1, the molecular weight of the polyester resin (RMPE) modified with a urea bond-forming group is lowered, and the hot offset resistance may be deteriorated.

  The mixing ratio of the isocyanate group-containing polyester prepolymer and the amines is not particularly limited and may be appropriately selected depending on the intended purpose. The isocyanate group [NCO] in the isocyanate group-containing polyester prepolymer is not limited. The mixing equivalent ratio [NCO] / [NHx] of amino groups [NHx] in the amines is preferably 1/3 to 3/1, more preferably 1/2 to 2/1, and 1/1. 5-1.5 / 1 is particularly preferred. If the mixing equivalent ratio ([NCO] / [NHx]) is less than 1/3, the low-temperature fixability may be reduced. If it exceeds 3/1, the molecular weight of the urea-modified polyester resin is reduced. Hot offset resistance may deteriorate.

--- Method for synthesizing polymer capable of reacting with active hydrogen group-containing compound ---
The method for synthesizing the polymer capable of reacting with the active hydrogen group-containing compound is not particularly limited and can be appropriately selected according to the purpose. For example, in the case of the isocyanate group-containing polyester prepolymer, the polyol and the Polycarboxylic acid is produced in the presence of a known esterification catalyst (titanium tetrabutoxide, dibutyltin oxide, etc.), heated to 150 ° C. to 280 ° C. while appropriately reducing the pressure as necessary, and water is distilled off to contain a hydroxyl group. Examples thereof include a method of synthesizing the polyester by reacting the hydroxyl group-containing polyester with the polyisocyanate at 40 to 140 ° C. after obtaining the polyester.

There is no restriction | limiting in particular as a weight average molecular weight (Mw) of the polymer which can react with the said active hydrogen group containing compound, Although it can select suitably according to the objective, Tetrahydrofuran (THF) soluble GPC (gel) The molecular weight distribution by permeation chromatography) is preferably 3,000 to 40,000, and more preferably 4,000 to 30,000. When the weight average molecular weight (Mw) is less than 3,000, the storage stability may be deteriorated, and when it exceeds 40,000, the low temperature fixability may be deteriorated. The weight average molecular weight (Mw) can be measured, for example, as follows. First, the column was stabilized in a 40 ° C. heat chamber, and at this temperature, tetrahydrofuran (THF) as a column solvent was flowed at a flow rate of 1 mL / min, and the sample concentration was adjusted to 0.05 to 0.6% by mass. Measurement is performed by injecting 50 μL to 200 μL of a tetrahydrofuran sample solution. In measuring the molecular weight of the sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of the calibration curve prepared by several monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, Pressure Chemical Co. Alternatively, Toyo Soda Kogyo's molecular weight is 6 × 10 ² , 2.1 × 10 ² , 4 × 10 ² , 1.75 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6. It is preferable to use those of × 10 ⁵ , 2 × 10 ⁶ , and 4.48 × 10 ⁶ and use at least about 10 standard polystyrene samples. An RI (refractive index) detector can be used as the detector.

―Colorant―
There is no restriction | limiting in particular as a coloring agent used for the toner of this invention, According to the objective, it can select suitably from a well-known coloring agent.

  The color of the colorant of the toner is not particularly limited and can be appropriately selected according to the purpose, and can be at least one selected from black toner, cyan toner, magenta toner, and yellow toner, Each color toner can be obtained by appropriately selecting the type of colorant, but is preferably a color toner.

  Examples of black products include carbon blacks (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, copper, iron (CI pigment black 11), titanium oxide, and the like. And organic pigments such as aniline black (CI Pigment Black 1).

  Examples of the magenta color pigment include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 48: 1, 49, 50, 51, 52, 53, 53: 1, 54, 55, 57, 57: 1, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 150, 163, 177, 179, 184, 202, 206, 207, 209, 211, 269; I. Pigment violet 19; C.I. I. Bat red 1, 2, 10, 13, 15, 23, 29, 35, etc. are mentioned.

  Examples of the color pigment for cyan include C.I. I. Pigment Blue 2, 3, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 60; I. Bat Blue 6; C.I. I. Acid Blue 45 and copper phthalocyanine pigments having 1 to 5 phthalimidomethyl groups substituted on the phthalocyanine skeleton, Green 7, Green 36, and the like.

  Examples of the color pigment for yellow include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 55, 65, 73, 74, 83, 97, 110, 139, 151, 154, 155, 180, 185; I. Bat yellow 1, 3, 20, orange 36 and the like.

  The content of the colorant in the toner is preferably 1% by mass to 15% by mass, and more preferably 3% by mass to 10% by mass. When the content is less than 1% by mass, the coloring power of the toner may be reduced. When the content is more than 15% by mass, poor dispersion of the pigment in the toner may occur. The characteristics may be degraded.

  The colorant may be used as a master batch combined with a resin. Such a resin is not particularly limited, but from the viewpoint of compatibility with the binder resin in the present invention, the binder resin of the present invention or a resin having a structure similar to the binder resin of the present invention should be used. Is preferred.

  The masterbatch can be produced by applying a high shear force and mixing or kneading the resin and the colorant. At this time, it is preferable to add an organic solvent in order to enhance the interaction between the colorant and the resin. Also, the so-called flushing method is preferable in that the wet cake of the colorant can be used as it is, and there is no need to dry it. The flushing method is a method in which an aqueous paste containing water of a colorant is mixed or kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove water and the organic solvent. For mixing or kneading, for example, a high shear dispersion device such as a three-roll mill can be used.

(Release agent)
The release agent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include plant waxes (carnauba wax, cotton wax, wood wax, rice wax, etc.), animal waxes (honey beeswax, lanolin). Waxes and waxes such as mineral wax (such as ozokerite and cercin), petroleum wax (such as paraffin, microcrystalline, and petrolatum); synthetic hydrocarbon wax (such as Fischer-Tropsch wax and polyethylene wax), and synthetic wax ( Esters, ketones, ethers, etc.) other than natural waxes; 1,2-hydroxystearic amide, stearic amide, phthalic anhydride, fatty acid amides such as chlorinated hydrocarbons; low molecular weight crystalline polymers Some polymethacrylate n-stearyl, polymethacrylate n Crystalline polymers having a long chain alkyl group in the side chain of the homopolymer or copolymer (acrylic acid n- stearyl over ethyl methacrylate copolymer, etc.) and the like polyacrylates lauryl and the like; and the like. Among these, since it can act effectively as a release agent between the fixing roller and the toner interface, high temperature offset resistance can be improved without applying a release agent such as oil to the fixing roller. A wax having a melting point of 50 ° C. to 120 ° C. is preferable because it can be used.

  There is no restriction | limiting in particular as melting | fusing point of the said mold release agent, Although it can select suitably according to the objective, 50 to 120 degreeC is preferable and 60 to 90 degreeC is more preferable. If the melting point is less than 50 ° C., the wax may adversely affect the storage stability, and if it exceeds 120 ° C., a cold offset may easily occur during fixing at a low temperature. The melting point of the release agent is determined by measuring the maximum endothermic peak using a differential scanning calorimeter (TG-DSC system, TAS-100, manufactured by Rigaku Corporation).

  The melt viscosity of the release agent is not particularly limited and may be appropriately selected depending on the intended purpose. However, the measured value at a temperature 20 ° C. higher than the melting point of the wax is preferably 5 cps to 1,000 cps, 10 cps to 100 cps is more preferable. If the melt viscosity is less than 5 cps, the releasability may be lowered, and if it exceeds 1,000 cps, the effect of improving hot offset resistance and low-temperature fixability may not be obtained.

  The release agent is preferably present in a dispersed state in the toner base particles, and for this purpose, the release agent and the binder resin are preferably incompatible with each other. The method for finely dispersing the release agent in the toner base particles is not particularly limited and may be appropriately selected depending on the purpose. For example, the release agent is dispersed by applying a kneading shear force during toner production. The method etc. are mentioned.

  The dispersion state of the release agent can be confirmed by observing a thin film slice of toner particles with a transmission electron microscope (TEM). The dispersion diameter of the release agent is preferably small, but if it is too small, there are cases where bleeding during fixing is insufficient. Therefore, if the release agent can be confirmed at a magnification of 10,000, the release agent is present in a dispersed state. When the release agent cannot be confirmed at 10,000 times, even when finely dispersed, the dyeing at the time of fixing becomes insufficient.

  There is no restriction | limiting in particular as content in the said toner of the said mold release agent, Although it can select suitably according to the objective, 1 mass%-20 mass% are preferable, and 3 mass%-10 mass% are more preferable. . When the content is less than 1% by mass, the hot offset resistance tends to deteriorate, and when it exceeds 20% by mass, the heat resistant storage stability, chargeability, transferability, and stress resistance tend to deteriorate. It is not preferable.

―Charge control agent―
Further, in order to impart an appropriate charging ability to the toner, a charge control agent can be contained in the toner as necessary.
Any known charge control agent can be used as the charge control agent. Since the color tone may change when a colored material is used, a colorless or nearly white material is preferable. Modified quaternary ammonium salts), alkylamides, phosphorus alone or compounds thereof, tungsten alone or compounds thereof, fluorine-based activators, metal salts of salicylic acid, metal salts of salicylic acid derivatives, and the like. These may be used individually by 1 type and may use 2 or more types together.

  The content of the charge control agent is determined by the toner production method including the type of the binder resin and the dispersion method, and is not uniquely limited. 01 mass%-5 mass% are preferable, and 0.02 mass%-2 mass% are more preferable. When the addition amount exceeds 5% by mass, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the developer fluidity is reduced, and the image The density may be lowered, and if it is less than 0.01% by mass, the charge start-up property and the charge amount are not sufficient, and the toner image may be easily affected.

―Layered inorganic mineral―
The layered inorganic mineral is not particularly limited as long as it is an inorganic mineral in which a layer having a thickness of several nm is laminated, and can be appropriately selected according to the purpose. For example, montmorillonite, bentonite, hectorite, attapulgite, Sepiolite, a mixture thereof and the like can be mentioned. These may be used alone or in combination of two or more. Among these, a modified layered inorganic mineral is preferable because it can be modified when the toner is granulated, has a charge control function, and is excellent in low-temperature fixing, and a layered inorganic mineral having a montmorillonite-based basic crystal structure is an organic cation. Organic modified montmorillonite and bentonite are particularly preferred from the viewpoint that the modified layered inorganic mineral modified with the above is more preferable, and the viscosity can be easily adjusted without affecting the toner characteristics.

  The modified layered inorganic compound preferably modifies at least part of the layered inorganic mineral with organic ions. By modifying at least a part of the layered inorganic mineral with organic ions, the layer has an appropriate hydrophobicity, the oil phase containing the toner composition and / or the toner composition precursor has a non-Newtonian viscosity, Can be modified.

  There is no restriction | limiting in particular as content in the toner base particle of the said modified | denatured layered inorganic mineral, Although it can select suitably according to the objective, 0.05 mass%-5 mass% are preferable.

-Toner production method-
The toner production method and materials in the present invention can be any known ones as long as they satisfy the conditions, and are not particularly limited. There is a so-called chemical method of granulating.
Examples of the chemical method include a suspension polymerization method, an emulsion polymerization method, a seed polymerization method, a dispersion polymerization method, etc., in which a monomer is used as a starting material; a resin or a resin precursor is dissolved in an organic solvent and the like in an aqueous medium. Dispersing or emulsifying dissolution suspension method; in the dissolution suspension method, an oil phase composition containing a resin precursor (reactive group-containing prepolymer) having a functional group capable of reacting with an active hydrogen group is contained in resin fine particles. A method of emulsifying or dispersing in an aqueous medium and reacting the active hydrogen group-containing compound and the reactive group-containing prepolymer in the aqueous medium (production method (I)); Phase inversion emulsification method in which water is added to a solution composed of an emulsifier; the resin particles obtained by these methods are aggregated in a state of being dispersed in an aqueous medium and granulated into particles of a desired size by heating and melting. Aggregation And the like. Among these, the toner obtained by the dissolution suspension method, the production method (I), and the aggregation method is preferable from the viewpoint of granulation properties (particle size distribution control, particle shape control, etc.) by the crystalline resin, and the production method described above. The toner obtained in (I) is more preferable.
In the following, a detailed description of these production methods will be given.

  The kneading and pulverizing method is, for example, a method of producing the toner base particles by pulverizing and classifying a toner material having at least a colorant, a binder resin, and a release agent melted and kneaded.

  In the melt kneading, the toner materials are mixed, and the mixture is charged into a melt kneader and melt kneaded. As the melt kneader, for example, a uniaxial or biaxial continuous kneader or a batch kneader using a roll mill can be used. For example, a KTK type twin screw extruder manufactured by Kobe Steel, a TEM type extruder manufactured by Toshiba Machine Co., Ltd., a twin screw extruder manufactured by Casey Kay, a PCM type twin screw extruder manufactured by Ikegai Iron Works, and a Kneader manufactured by Buss Co., Ltd. are suitable. Used. This melt-kneading is preferably performed under appropriate conditions so as not to cause the molecular chains of the binder resin to be broken. Specifically, the melt-kneading temperature is determined with reference to the softening point of the binder resin. If the temperature is higher than the softening point, cutting is severe, and if the temperature is too low, dispersion may not proceed.

  In the pulverization, the kneaded product obtained by the kneading is pulverized. In this pulverization, it is preferable that the kneaded material is first coarsely pulverized and then finely pulverized. At this time, a method of pulverizing by colliding with a collision plate in a jet stream, pulverizing particles by colliding with each other in a jet stream, or pulverizing with a narrow gap between a mechanically rotating rotor and a stator is preferably used.

In the classification, the pulverized product obtained by the pulverization is classified and adjusted to particles having a predetermined particle diameter. The classification can be performed, for example, by removing the fine particle portion with a cyclone, a decanter, a centrifuge, or the like.
After the pulverization and classification are completed, the pulverized product is classified into an air stream by centrifugal force or the like, and toner base particles having a predetermined particle diameter can be produced.

  In the dissolution suspension method, for example, an oil phase composition in which a toner composition containing at least a binder resin or a resin precursor, a colorant, and a release agent is dissolved or dispersed in an organic solvent is used. This is a method for producing toner base particles by dispersing or emulsifying in a medium.

The organic solvent used for dissolving or dispersing the toner composition is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal of the solvent later.
Examples of the organic solvent include ester solvents such as ethyl acetate, butyl acetate, methoxybutyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, diethyl ether, tetrahydrofuran, dioxane, ethyl cellosolve, butyl cellosolve, and propylene glycol monomethyl. Ether solvents such as ether, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, di-n-butyl ketone, cyclohexanone, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, 2 -Alcohol solvents, such as ethyl hexyl alcohol and benzyl alcohol, and these 2 or more types of mixed solvents are mentioned.

In the dissolution suspension method, when the oil phase composition is dispersed or emulsified in an aqueous medium, an emulsifier or a dispersant may be used as necessary.
As the emulsifier or dispersant, known surfactants, water-soluble polymers and the like can be used. The surfactant is not particularly limited, and is an anionic surfactant (alkyl benzene sulfonic acid, phosphate ester, etc.), a cationic surfactant (quaternary ammonium salt type, amine salt type, etc.), an amphoteric surfactant (carbon carboxyl). Acid salt type, sulfate ester type, sulfonate salt type, phosphate ester salt type, etc.), nonionic surfactants (AO addition type, polyhydric alcohol type, etc.) and the like. One surfactant may be used alone, or two or more surfactants may be used in combination.
Examples of the water-soluble polymer include cellulose compounds (for example, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose and saponified products thereof), gelatin, starch, dextrin, gum arabic, chitin, chitosan. , Polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, polyethyleneimine, polyacrylamide, acrylic acid (salt) -containing polymer (sodium polyacrylate, potassium polyacrylate, ammonium polyacrylate, partially neutralized sodium hydroxide of polyacrylic acid) , Sodium acrylate-acrylic acid ester copolymer), sodium hydroxide of styrene-maleic anhydride copolymer ( Min) neutralized product water-soluble polyurethane (polyethylene glycol, reaction products of polycaprolactone diol with polyisocyanate and the like) and the like.
Moreover, said organic solvent, a plasticizer, etc. can also be used together as an auxiliary | assistant of emulsification or dispersion | distribution.

  The toner according to the present invention includes at least a binder resin, a binder resin precursor having a functional group capable of reacting with an active hydrogen group (reactive group-containing prepolymer), a colorant, and a release agent in a dissolution suspension method. An active phase group-containing prepolymer and an active hydrogen group-containing compound contained in the oil phase composition and / or the aqueous medium are dispersed or emulsified in an aqueous medium containing resin fine particles. It is preferable to obtain the toner base particles by a method of reacting with (the production method (I)).

The resin fine particles can be formed using a known polymerization method, but is preferably obtained as an aqueous dispersion of resin fine particles. Examples of the method for preparing an aqueous dispersion of resin fine particles include the methods shown in the following (a) to (h).
(A) A method in which an aqueous dispersion of resin fine particles is directly prepared from a vinyl monomer as a starting material by any one of a suspension polymerization method, an emulsion polymerization method, a seed polymerization method and a dispersion polymerization method. (B) After dispersing a precursor of polyaddition or condensation resin such as polyester resin, polyurethane resin, epoxy resin (monomer, oligomer, etc.) or a solvent solution thereof in an aqueous medium in an aqueous medium, A method of preparing an aqueous dispersion of resin fine particles by heating or adding a curing agent to cure.
(C) Polyaddition or condensation resin precursors (monomers, oligomers, etc.) such as polyester resins, polyurethane resins, and epoxy resins, or solvent solutions thereof (preferably liquids, which may be liquefied by heating). A method for preparing an aqueous dispersion of resin fine particles by dissolving a suitable emulsifier in the mixture and then adding water to effect phase inversion emulsification.
(D) A resin synthesized in advance by a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) is pulverized and classified using a mechanical rotary type or jet type fine pulverizer. A method of preparing an aqueous dispersion of resin fine particles by obtaining resin fine particles and then dispersing in water in the presence of an appropriate dispersant.
(E) Fine resin particles are formed by spraying a resin solution in which a resin synthesized in advance by a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) is dissolved in a solvent. Then, resin fine particles are dispersed in water in the presence of a suitable dispersant to prepare an aqueous dispersion of resin fine particles.
(F) A poor solvent is added to a resin solution prepared by previously dissolving a resin synthesized by a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent, or heated to a solvent in advance. By cooling the dissolved resin solution, the resin fine particles are precipitated, the solvent is removed to form the resin fine particles, and then the resin fine particles are dispersed in water in the presence of an appropriate dispersant to disperse the resin fine particles in water. A method for preparing a liquid.
(G) A resin solution obtained by dissolving a resin previously synthesized by a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent in the presence of an appropriate dispersant. A method of preparing an aqueous dispersion of resin fine particles by dispersing in a solvent and then removing the solvent by heating, decompression or the like.
(H) A suitable emulsifier is dissolved in a resin solution prepared by previously dissolving a resin synthesized by a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent, and then water To prepare an aqueous dispersion of resin fine particles by phase inversion emulsification.

  The volume average particle diameter of the resin fine particles is preferably 10 nm or more and 300 nm or less, and more preferably 30 nm or more and 120 nm or less. When the volume average particle size of the resin fine particles is less than 10 nm or more than 300 nm, the particle size distribution of the toner may be deteriorated.

  The solid content concentration of the oil phase is preferably about 40 to 80%. If the concentration is too high, dissolution or dispersion becomes difficult, and the viscosity becomes high and difficult to handle. If the concentration is too low, the productivity of the toner decreases.

  The toner composition other than the binder resin such as the colorant and the release agent, and the masterbatch thereof are individually dissolved or dispersed in an organic solvent, and then mixed with the binder resin solution or dispersion. May be.

  As the aqueous medium, water alone may be used, but a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.) and the like.

  The dispersion or emulsification method in the aqueous medium is not particularly limited, and known equipment such as a low-speed shearing type, a high-speed shearing type, a friction type, a high-pressure jet type, and an ultrasonic wave can be applied. Among these, the high-speed shearing method is preferable from the viewpoint of reducing the particle size of the particles. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 20 to 80 ° C.

  In order to remove the organic solvent from the obtained emulsified dispersion, there is no particular limitation, and a known method can be used. For example, the whole system is gradually raised while stirring the whole system under normal pressure or reduced pressure. A method of warming and completely evaporating and removing the organic solvent in the droplets can be employed.

  As a method of washing and drying the toner base particles dispersed in the aqueous medium, a known technique is used. That is, after solid-liquid separation with a centrifuge, a filter press, etc., the obtained toner cake is redispersed in ion exchange water at about room temperature to about 40 ° C., and after adjusting the pH with acid or alkali as necessary, After removing the impurities and surfactants by repeating the process of solid-liquid separation again and again, the toner powder is obtained by drying with an air dryer, circulating dryer, vacuum dryer, vibration fluid dryer, etc. . At this time, the fine particle component of the toner may be removed by centrifugation or the like, and a desired particle size distribution can be obtained using a known classifier after drying, if necessary.

  In the agglomeration method, for example, a toner base particle is produced by mixing and aggregating a resin fine particle dispersion comprising at least a binder resin, a colorant particle dispersion, and a release agent particle dispersion as necessary. is there. The resin fine particle dispersion is obtained by a known method such as emulsion polymerization, seed polymerization, phase inversion emulsification, and the like. The colorant particle dispersion and the release agent particle dispersion are obtained by a known wet dispersion method. It can be obtained by dispersing a colorant or a release agent in an aqueous medium.

For the control of the aggregation state, methods such as applying heat, adding a metal salt, and adjusting pH are preferably used.
There is no restriction | limiting in particular as said metal salt, The monovalent metal which comprises salts, such as sodium and potassium; The bivalent metal which comprises salts, such as calcium and magnesium; The trivalent metal which comprises salts, such as aluminum, etc. Is mentioned.
Examples of the anion constituting the salt include chloride ion, bromide ion, iodide ion, carbonate ion, and sulfate ion. Among these, magnesium chloride, aluminum chloride, and complexes and multimers thereof are preferable. .
In addition, heating between the agglomeration and after completion of the agglomeration can promote fusion of the resin fine particles, which is preferable from the viewpoint of toner uniformity. Furthermore, the shape of the toner can be controlled by heating. Normally, the toner becomes more spherical when heated further.

  As the method for washing and drying the toner base particles dispersed in the aqueous medium, the above-described method and the like can be used.

Further, in order to improve the fluidity, storage stability, developability, and transferability of the toner, the coalesced particles are added to and mixed with the toner base particles produced as described above. Inorganic fine particles may be added and mixed.
For mixing the additives, a general powder mixer is used, but it is preferable to equip a jacket or the like to adjust the internal temperature. In order to change the load history applied to the additive, the additive may be added midway or gradually. In this case, you may change the rotation speed, rolling speed, time, temperature, etc. of a mixer. Alternatively, a strong load may be applied first, then a relatively weak load, or vice versa. Examples of the mixing equipment that can be used include a V-type mixer, a rocking mixer, a Ladige mixer, a Nauter mixer, and a Henschel mixer. Next, the toner is obtained by passing through a sieve of 250 mesh or more to remove coarse particles and aggregated particles.

  The shape, size, etc. of the toner are not particularly limited and can be appropriately selected according to the purpose. The average circularity, volume average particle size, volume average particle size and number are as follows. It is preferable to have a ratio (volume average particle diameter / number average particle diameter) to the average particle diameter.

The average circularity is a value obtained by dividing the circumference of an equivalent circle having the same projected shape as the shape of the toner by the circumference of the actual particles. For example, 0.950 to 0.980 is preferable, and 0.960 to 0 is preferable. .975 is more preferred. In addition, it is preferable that the average circularity is less than 0.95.
When the average circularity is less than 0.950, satisfactory transferability and a high-quality image free from dust may not be obtained. When the average circularity exceeds 0.980, image formation employing blade cleaning or the like is employed. In the system, defective cleaning on the photoconductor and transfer belt occurs, and in the case of image formation with a high image area ratio such as photographic images, an untransferred image is formed due to poor paper feed, etc. The accumulated toner may become a transfer residual toner on the photoconductor, resulting in background smearing of the image, or it may contaminate the charging roller for charging the photoconductor in contact with the original charging ability. It may become impossible to demonstrate.

  The average circularity is measured using a flow particle image analyzer (“FPIA-2100”, manufactured by Sysmex Corporation), and analyzed using analysis software (FPIA-2100 Data Processing Program for FPIA version 00-10). It was. Specifically, 0.1 to 0.5 ml of 10% by weight surfactant (alkylbenzene sulfonate, Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added to a 100 ml glass beaker, and each toner 0 is added. 0.1 to 0.5 g was added, and the mixture was mixed with a micropartel, and then 80 mL of ion-exchanged water was added. The obtained dispersion was subjected to a dispersion treatment for 3 minutes with an ultrasonic disperser (manufactured by Honda Electronics Co., Ltd.). The shape and distribution of the toner were measured using the FPIA-2100 until the concentration of the dispersion reached 5,000 to 15,000 / μL. In this measurement method, it is important that the concentration of the dispersion is 5,000 to 15,000 / μL from the viewpoint of measurement reproducibility of average circularity. In order to obtain the concentration of the dispersion, it is necessary to change the conditions of the dispersion, that is, the amount of surfactant to be added and the amount of toner. The amount of the surfactant varies depending on the hydrophobicity of the toner as in the measurement of the toner particle diameter described above. If it is added in a large amount, noise due to bubbles is generated, and if it is too small, the toner cannot be sufficiently wetted. It will be enough. The amount of toner added varies depending on the particle size, and is small when the particle size is small, and needs to be increased when the particle size is large. When the toner particle size is 3 μm to 10 μm, the toner amount is 0.1 g to 0.00 g. By adding 5 g, the dispersion concentration can be adjusted to 5,000 / μl to 15,000 / μl.

  There is no restriction | limiting in particular as a volume average particle diameter of the said toner, Although it can select suitably according to the objective, For example, 3 micrometers-10 micrometers are preferable, and 4 micrometers-7 micrometers are more preferable. When the volume average particle size is less than 3 μm, in the case of a two-component developer, the toner may be fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier may be reduced. Therefore, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed, the variation in the toner particle size may increase.

The ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) in the toner is preferably 1.00 to 1.25, and more preferably 1.00 to 1.15.
The volume average particle diameter and the ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) are measured using a particle size measuring device (“Multisizer III”, manufactured by Beckman Coulter, Inc.). Then, measurement was performed with an aperture diameter of 100 μm, and analysis was performed with analysis software (Beckman Coulter Multisizer 3 Version 3.51). Specifically, 0.5 ml of 10% by weight surfactant (alkylbenzene sulfonate, Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added to a 100 ml beaker made of glass, and 0.5 g of each toner is added. The mixture was stirred with a micropartel, and then 80 ml of ion exchange water was added. The obtained dispersion was subjected to a dispersion treatment for 10 minutes with an ultrasonic disperser (W-113MK-II, manufactured by Honda Electronics Co., Ltd.). The dispersion was measured using the Multisizer III and Isoton III (manufactured by Beckman Coulter, Inc.) as the measurement solution. In the measurement, the toner sample dispersion was dropped so that the concentration indicated by the apparatus was 8 ± 2%. In this measurement method, it is important that the concentration is 8 ± 2% from the viewpoint of the reproducibility of the particle size. Within this concentration range, no error occurs in the particle size.

(Developer)
The developer in the present invention is a two-component developer containing a toner and a carrier. When used in a high-speed printer or the like corresponding to the recent improvement in information processing speed, the two-component developer is preferable in terms of improving the service life.
The two-component developer using the toner has little fluctuation in the toner particle diameter in the developer even if the toner balance is maintained over a long period of time. Is obtained.

(Career)
The carrier of the present invention is not particularly limited as long as it satisfies the above formula (1), and can be appropriately selected according to the purpose. The core particle and a resin layer (coating covering the core particle) Having a layer) is preferred. Furthermore, it has the core particle which has magnetism, and the coating layer which coat | covers this core particle, shape factor SF-2 is 115-150, and bulk density is 1.8-2.4 g / cm < ³ >. Yes, the core particle has a shape factor SF-2 of 120 to 160, the arithmetic average surface roughness Ra of the core particle is 0.5 to 1.0 μm, and the coating layer contains a resin and inorganic fine particles And it is preferable to contain this inorganic fine particle in the ratio of 50-500 mass parts with respect to 100 mass parts of this resin.
By combining with a carrier having the specific shape, bulk density, and the like, the occurrence of a hysteresis phenomenon can be similarly suppressed in an image forming apparatus equipped with a toner having excellent low-temperature fixability.

<Core particles>
The core particles are not particularly limited as long as they are magnetic core particles, and can be appropriately selected according to the purpose. For example, ferromagnetic metals such as iron and cobalt; oxidation of magnetite, hematite, ferrite, and the like Iron; resin particles in which magnetic materials such as various alloys and compounds are dispersed in a resin. Among these, Mn-based ferrite, Mn-Mg-based ferrite, Mn-Mg-Sr-based ferrite and the like are preferable from the viewpoint of environmental considerations.

-Core particle shape factor SF-1-
The core particles are defined by the shape factor SF-1.
SF-1 defines the degree of roundness of the particles.
As the value of SF-1 increases, the shape of the particles moves away from the circle (spherical shape).

  There is no restriction | limiting in particular as the shape factor SF-1 of the said core particle, According to the objective, it can select suitably.

The measurement of the core particle shape factor SF-1 is performed by measuring the particle image of the core particle magnified 300 times using a scanning electron microscope (for example, FE-SEM (S-800), manufactured by Hitachi, Ltd.). Individual sampling was performed, and the obtained image information was analyzed by an image analyzer (for example, Luzex AP, manufactured by Nireco) and calculated by using the following formula (I).
SF-1 = (L ² / A) × (π / 4) × 100 (I)
However, in said formula (I), L represents the absolute maximum length (length of a circumscribed circle) of particle | grains, and A represents the projection area of particle | grains.

-Shape factor SF-2- of core particle
The core particles are defined by the shape factor SF-2.
SF-2 defines the degree of unevenness of particles.
When the value of SF-2 increases, the unevenness of the surface of the particles becomes severe.

  The shape factor SF-2 of the core particle is not particularly limited as long as it is 120 to 160, and can be appropriately selected according to the purpose. When the shape factor SF-2 is less than 120, the convex portions of the core particles are likely to be covered, and it may be difficult to form a local low resistance. Further, when the shape factor SF-2 exceeds 160, not only the voids in the core particles are increased and the strength of the core particles is weakened, but also when the core is used in a developing device for a long period of time. There are many exposures of particles, and the change of the initial resistance value and the resistance value after use becomes large, the amount of toner on the electrostatic latent image carrier and how the toner image is formed fluctuate, and the image density may fluctuate. is there.

The core particle shape factor SF-2 was measured by measuring 100 particle images of core particles magnified 300 times using a scanning electron microscope (for example, FE-SEM (S-800), manufactured by Hitachi, Ltd.). Random sampling was performed, and the obtained image information was analyzed by an image analyzer (for example, Luzex AP, manufactured by Nireco) and calculated using the following formula (II).
SF-2 = (P ² / A) × (1 / 4π) × 100 (II)
However, in said Formula (II), P represents the circumference of a core particle and A represents the projection area of a core particle.

-Arithmetic average surface roughness Ra of core particles-
The arithmetic average surface roughness Ra of the core particles defines the surface roughness of the core particles.
The arithmetic average surface roughness Ra of the core particles is preferably 0.5 μm to 1.0 μm, and more preferably 0.6 μm to 0.9 μm. When the arithmetic average surface roughness Ra of the core particles is less than 0.5 μm, the arithmetic average surface roughness of the carrier after forming the coating layer becomes too small, and the contact between the carrier and the toner decreases, and the toner -Adhesive force between the carriers does not work properly, and the toner adheres and remains on the developer carrying member, which may cause a hysteresis phenomenon, which is not preferable. When the arithmetic average surface roughness Ra of the core particles exceeds 1.0 μm, the arithmetic average surface roughness of the carrier after forming the coating layer becomes too large, and the carrier particles are convex when used in a developing device for a long time. The wear of the coating layer at the part becomes remarkable, the change of the resistance value over time from the initial resistance value becomes large, the amount of toner on the electrostatic latent image carrier, the way of forming the toner image fluctuates, The image density may fluctuate, which is not preferable.

  The measurement of the arithmetic average surface roughness Ra of the core particles is performed using an optical microscope (for example, OPTELICS C130, manufactured by LASERTEC) after setting an objective lens magnification of 50 times and capturing an image with a resolution of 0.20 μm. The observation area was 10 μm × 10 μm centering on the apex of the core particles, and the average value of the surface roughness Ra of 100 core particles was measured.

-Weight average particle diameter Dw of core particles-
The weight average particle diameter Dw of the core particles refers to the particle diameter at an integrated value of 50% in the particle size distribution of the core particles obtained by a laser diffraction or scattering method. There is no restriction | limiting in particular as the weight average particle diameter Dw of the said core particle, Although it can select suitably according to the objective, 10 micrometers-80 micrometers are preferable.

The weight average particle diameter Dw of the core particles is measured by using a microtrac particle size distribution meter (HRA9320-X100, manufactured by Honeywell) as a particle size distribution (relationship between number frequency and particle size) of particles measured on a number basis. And measured under the conditions described below, and calculated using the following formula (III). Each channel represents a length for dividing the particle size range in the particle size distribution chart into measurement width units, and the lower limit value of the particle size stored in each channel is adopted as the representative particle size.
Dw = {1 / Σ (nD ³ )} × {Σ (nD ⁴ )} (III)
In the formula (III), D represents the representative particle size (μm) of the core particles present in each channel, and n represents the total number of core particles present in each channel.
[Measurement condition]
[1] Particle size range: 100 μm to 8 μm
[2] Channel length (channel width): 2 μm
[3] Number of channels: 46
[4] Refractive index: 2.42

<Coating layer>
The coating layer is formed of a coating layer forming solution containing a resin and a filler, and the filler is preferably inorganic fine particles.
The coating layer is not particularly limited as long as it is a coating layer containing the filler in a proportion of 50 to 500 parts by mass with respect to 100 parts by mass of the resin, and can be appropriately selected according to the purpose. However, a coating layer containing 100 to 300 parts by mass of the filler with respect to 100 parts by mass of the resin is preferable. When the content of the filler is less than 50 parts by mass, the coating layer may be scraped. When the content exceeds 500 parts by mass, the proportion of the resin that appears on the surface of the carrier becomes relatively small, and the toner May be easily spent on the carrier surface. On the other hand, when the content is within the preferable range, it is advantageous in that the coating layer is less likely to be scraped when used for a long time in a developing machine.

  If the coating layer is too thin, the surface of the core particles may be easily exposed by stirring in a developing machine, and the change in resistance value may increase. The convex portion is not exposed, and it becomes difficult to form a local low resistance state. The thickness of the coating layer can be controlled by the content of the resin with respect to the core particles. There is no restriction | limiting in particular as content with respect to the said core particle of the said resin, Although it can select suitably according to the objective, A local low resistance state can be formed with the thickness of a coating layer, 0 0.5 mass%-3.0 mass% are preferable.

-Resin-
The resin is not particularly limited and may be appropriately selected depending on the purpose. For example, acrylic resin, amino resin, polyvinyl resin, polystyrene resin, halogenated olefin resin, polyester, polycarbonate, polyethylene, polyfluoride Fluorine such as vinyl, polyvinylidene fluoride, polytrifluoroethylene, polyhexafluoropropylene, copolymers of vinylidene fluoride and vinyl fluoride, terpolymers of tetrafluoroethylene, vinylidene fluoride and non-fluorinated monomers Examples include terpolymers and silicone resins. These may be used individually by 1 type and may use 2 or more types together. Among these, a silicone resin is preferable.

  There is no restriction | limiting in particular as said resin, Although it can select suitably according to the objective, Resin containing the hardened | cured material of the mixture containing a silane coupling agent and a silicone resin is preferable.

--Silicone resin--
There is no restriction | limiting in particular as said silicone resin, Although it can select suitably according to the objective, At least A part represented by the following general formula (A), and B part represented by the following general formula (B) A resin containing a cross-linked product obtained by hydrolyzing a copolymer containing and producing a silanol group and condensing is preferable.
In the general formula (A), R ¹ represents a hydrogen atom or a methyl group,, R ² represents an alkyl group having 1 to 4 carbon atoms, m is an integer of 1 to 8 X represents a molar ratio in the copolymer, and represents 10 mol% to 90 mol%.
However, the general formula (B), R ¹ represents a hydrogen atom or a methyl group, R ² represents an alkyl group having 1 to 4 carbon atoms, R ³ is 1 to carbon atoms 8 represents an alkyl group of 1 or an alkoxy group having 1 to 4 carbon atoms, m represents an integer of 1 to 8, Y represents a molar ratio in the copolymer, and represents 10 mol% to 90 mol. %.

--Silane coupling agent--
The silane coupling agent can stably disperse the filler.
There is no restriction | limiting in particular as said silane coupling agent, According to the objective, it can select suitably, For example, r- (2-aminoethyl) aminopropyl trimethoxysilane, r- (2-aminoethyl) aminopropyl Methyldimethoxysilane, r-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) -r-aminopropyltrimethoxysilane hydrochloride, r-glycidoxypropyltrimethoxysilane, r-mercaptopropyl Trimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltriacetoxysilane, r-chloropropyltrimethoxysilane, hexamethyldisilazane, r-anilinopropyltrimethoxysilane, vinyltrimethoxysilane, octadecyldimethyl [3 (Trimethoxysilyl) propyl] ammonium chloride, r-chloropropylmethyldimethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, allyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane Dimethyldiethoxysilane, 1,3-divinyltetramethyldisilazane, methacryloxyethyldimethyl (3-trimethoxysilylpropyl) ammonium chloride, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Examples of commercially available silane coupling agents include AY43-059, SR6020, SZ6023, SH6020, SH6026, SZ6032, SZ6050, AY43-310M, SZ6030, SH6040, AY43-026, AY43-031, sh6062, Z-6911. , Sz6300, sz6075, sz6079, sz6083, sz6070, sz6072, Z-6721, AY43-004, Z-6187, AY43-021, AY43-043, AY43-040, AY43-047, Z-6265, AY43-204M, AY43 -048, Z-6403, AY43-206M, AY43-206E, Z6341, AY43-210MC, AY43-083, AY43-101, AY43-013, AY4 -158E, Z-6920, Z-6940 (all manufactured by Dow Corning Toray Co., Ltd.).

  There is no restriction | limiting in particular as an addition amount of the said silane coupling agent, Although it can select suitably according to the objective, 0.1 mass%-10 mass% are preferable with respect to the said resin. When the addition amount is less than 0.1% by mass, the adhesiveness of the core particles, the filler, and the resin is lowered, and the coating layer may fall off during long-term use. If it exceeds 1, toner filming may occur during long-term use.

-Filler-
There is no restriction | limiting in particular as said filler, According to the objective, it can select suitably, For example, a conductive filler, a nonelectroconductive filler, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, it is preferable to contain a conductive filler and a non-conductive filler in the coating layer.

The conductive filler refers to a filler having a powder specific resistance value of 100 Ω · cm or less.
The said nonelectroconductive filler points out the filler whose powder specific resistance value exceeds 100 ohm * cm.
The powder specific resistance value of the filler is measured by a powder resistance measurement system (MCP-PD51, manufactured by Dia Instruments) and a resistivity meter (4-terminal 4-probe system, Loresta GP, manufactured by Mitsubishi Chemical Analytech). Was measured under the conditions of a sample of 1.0 g, an electrode interval of 3 mm, a sample radius of 10.0 mm, and a load of 20 kN.

--Conductive filler--
The conductive filler is not particularly limited and may be appropriately selected depending on the intended purpose. For example, tin oxide or oxide may be applied to a substrate such as aluminum oxide, titanium oxide, zinc oxide, barium sulfate, silicon oxide, or zirconium oxide. Examples thereof include a conductive filler formed using indium as a layer; a conductive filler formed using carbon black, and the like. Among these, a conductive filler containing aluminum oxide, titanium oxide, and barium sulfate is preferable.

--Non-conductive filler--
There is no restriction | limiting in particular as said nonelectroconductive filler, According to the objective, it can select suitably, For example, it forms using aluminum oxide, titanium oxide, barium sulfate, zinc oxide, silicon dioxide, zirconium oxide etc. Non-conductive filler etc. are mentioned. Among these, non-conductive fillers containing aluminum oxide, titanium oxide, and barium sulfate are preferable.

--Number average particle diameter of filler--
The number average particle diameter of the filler is not particularly limited and may be appropriately selected depending on the purpose. However, the filler is likely to come out from the surface of the resin contained in the coating layer, and a partial low resistance is obtained. 50 nm to 800 nm is preferable, and 200 nm to 700 nm is more preferable in that it is easy to make, easy to scrape the spent on the carrier surface, and excellent in wear resistance. The number average particle diameter of the filler is measured by randomly measuring 100 particle images of the filler magnified 10,000 times using a scanning electron microscope (for example, FE-SEM (S-800), manufactured by Hitachi, Ltd.). The particle size was measured by sampling and the number average particle size was used.

<Other ingredients>
There is no restriction | limiting in particular as said other component, Although it can select suitably according to the objective, It is preferable to contain a catalyst in the said coating layer, and you may contain a solvent, a hardening | curing agent, etc.

-Catalyst-
The catalyst is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include titanium-based catalysts, tin-based catalysts, zirconium-based catalysts, aluminum-based catalysts, and the like. Examples include acetylacetonato complex, alkylacetoacetate complex, salicylaldehyde complex and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, a titanium-based catalyst is preferable and titanium diisopropoxybis (ethyl acetoacetate) is more preferable in that the effect of promoting the condensation reaction of the silanol group is large and the catalyst is difficult to deactivate.

<Carrier manufacturing method>
There is no restriction | limiting in particular as a manufacturing method of the said carrier, Although it can select suitably according to the objective, The said resin and the said filler are contained in the surface of the said core particle using a fluid bed type coating apparatus. The method of manufacturing by apply | coating a coating layer forming solution is preferable. In addition, when apply | coating the said coating layer formation solution, you may advance condensation of the resin contained in the said coating layer, and after apply | coating the said coating layer formation solution, condensation of the resin contained in the said coating layer You may proceed. There is no restriction | limiting in particular as the condensation method of the said resin, According to the objective, it can select suitably, For example, the method etc. which give a heat | fever, light, etc. to the said coating layer formation solution, etc. are mentioned. .

-Career work function Wc-
The work function Wc of the carrier in the formula (1) is, for example, changing the type and addition amount of the silane coupling agent, the type of resin constituting the coating layer, the type of filler, the addition amount, etc. Thus, the desired value can be controlled.

-Carrier shape factor SF-2-
The carrier is defined by the shape factor SF-2.
SF-2 defines the degree of unevenness of particles.
When the value of SF-2 increases, the unevenness of the surface of the particles becomes severe.

  The carrier shape factor SF-2 is not particularly limited as long as it is 115 to 150, and can be appropriately selected according to the purpose. 145 is preferred.

The carrier shape factor SF-2 is measured by randomly measuring 100 particle images of the carrier magnified 300 times using a scanning electron microscope (for example, FE-SEM (S-800), manufactured by Hitachi, Ltd.). Sampling was performed, and the obtained image information was analyzed by an image analyzer (for example, Luzex AP, manufactured by Nireco) and calculated by using the following formula (IV).
SF-2 = (P ² / A) × (1 / 4π) × 100 (IV)
However, in said Formula (IV), P represents the circumference of a carrier and A represents the projected area of a carrier.

-Bulk density of carrier-
The bulk density of the carrier is not particularly limited as long as the bulk density is 1.80 g / cm ^{3 to} 2.40 g / cm ³ , and can be appropriately selected according to the purpose. The bulk density is less than 1.80 g / cm ^3, the carrier is liable to cause so-called carrier adhesion to adhere to the electrostatic latent image bearing member, exceeds 2.40 g / cm ^3, agitation in the developing machine Stress may increase and carrier resistance change may increase.

The bulk density of the carrier was measured by dropping it from a height of 25 mm into a 25 cm ³ container from a funnel having an orifice diameter of ³ mm.

-Weight average particle diameter Dw of carrier-
The weight average particle diameter Dw of the carrier refers to the particle diameter at an integrated value of 50% in the particle size distribution of the core particles obtained by a laser diffraction / scattering method. There is no restriction | limiting in particular as the weight average particle diameter Dw of the said carrier, Although it can select suitably according to the objective, 10 micrometers-80 micrometers are preferable.

For the measurement of the weight average particle diameter Dw of the carrier, the particle size distribution (relationship between the number frequency and the particle diameter) of the particles measured on the basis of the number is used using a Microtrac particle size distribution meter (HRA9320-X100, manufactured by Honeywell). Measured under the conditions described below, and calculated using the following formula (V). Each channel represents a length for dividing the particle size range in the particle size distribution chart into measurement width units, and the lower limit value of the particle size stored in each channel is adopted as the representative particle size.
Dw = {1 / Σ (nD ³ )} × {Σ (nD ⁴ )} (V)
In the above formula (V), D represents the representative particle size (μm) of carriers present in each channel, and n represents the total number of carriers present in each channel.
[Measurement condition]
[1] Particle size range: 100 μm to 8 μm
[2] Channel length (channel width): 2 μm
[3] Number of channels: 46
[4] Refractive index: 2.42

  When the developer is a two-component developer, the mixing ratio of the toner and the carrier in the two-component developer is preferably such that the mass ratio of the toner to the carrier is 2.0 to 12.0% by mass, More preferably, it is 2.5-10.0 mass%.

(Image forming method and image forming apparatus)
The image forming method used in the present invention includes at least an electrostatic latent image forming step (charging step and exposure step), a developing step, a transfer step, and a fixing step, and other types appropriately selected as necessary. The process includes, for example, a static elimination process, a cleaning process, a recycling process, a control process, and the like.
The image forming apparatus of the present invention includes an electrostatic latent image carrier, a charging unit for charging the surface of the electrostatic latent image carrier, and exposing the surface of the electrostatic latent image carrier to expose the electrostatic latent image. An exposure unit that forms a visible image by developing the electrostatic latent image with toner, a transfer unit that transfers the visible image to a recording medium, and a transfer unit that transfers the visible image to the recording medium. And a fixing means for fixing the transferred image, and further, other means appropriately selected as necessary, for example, a discharging means, a cleaning means, a recycling means, a control means, and the like. The developing means is the developing device of the present invention.

-Electrostatic latent image forming process and electrostatic latent image forming means-
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
The electrostatic latent image carrier (sometimes referred to as “electrophotographic photosensitive member” or “photosensitive member”) is not particularly limited in terms of material, shape, structure, size, etc. Although it can be selected as appropriate, the shape thereof is preferably a drum shape, and examples of the material thereof include inorganic photoreceptors such as amorphous silicon and selenium, organic photoreceptors (OPC) such as polysilane and phthalopolymethine, and the like. Is mentioned. Among these, amorphous silicon or the like is preferable in terms of long life.

The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then performing imagewise exposure, and is performed by electrostatic latent image forming means. Can do.
The electrostatic latent image forming unit includes, for example, a charging unit (charger) that uniformly charges the surface of the electrostatic latent image carrier, and an exposure that exposes the surface of the electrostatic latent image carrier imagewise. Means (exposure unit).

The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roll, brush, film, rubber blade, etc. And non-contact chargers utilizing corona discharge such as corotrons and corotrons.
The charger is preferably one that is arranged in contact or non-contact with the electrostatic latent image carrier and charges the surface of the electrostatic latent image carrier by applying a direct current and an alternating voltage.
The charger is a charging roller that is disposed in close proximity to the electrostatic latent image carrier via a gap tape. The electrostatic latent image carrier is applied by applying a direct current and an alternating voltage to the charging roller. Those that charge the body surface are preferred.

The exposure can be performed, for example, by exposing the surface of the latent electrostatic image bearing member imagewise using the exposure device.
The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger so as to form an image to be formed, and is appropriately selected according to the purpose. For example, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used.
In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

-Development process and development means-
The developing step is a step of developing the electrostatic latent image using the developer to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the developer, and can be performed by the developing unit.
The developing means preferably has, for example, at least a developing unit that accommodates the developer and can apply the developer to the electrostatic latent image in a contact or non-contact manner, and includes a developer-containing container. More preferred is a developing device.

The developing device may be a single color developing device or a multicolor developing device. For example, a stirrer that frictionally stirs and charges the developer and a rotatable magnet roller (developing) And the like having an agent carrier).
In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrostatic latent image carrier (photoconductor), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted. It moves to the surface of the electrostatic latent image carrier (photoconductor) by force. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrostatic latent image carrier (photoconductor).

―Transfer process and transfer means―
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the electrostatic latent image carrier (photoconductor) with the transfer charger using the visible image, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

The transfer means (the primary transfer means and the secondary transfer means) is a transfer for peeling and charging the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have at least a vessel. The number of the transfer means may be one, or two or more.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is not particularly limited and can be appropriately selected from known recording media (recording paper).

―Fixing process and fixing means―
The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the developer of each color is transferred to the recording medium, or the developer of each color. On the other hand, it may be carried out at the same time in a state where these are laminated.
There is no restriction | limiting in particular as said fixing device, Although it can select suitably according to the objective, A well-known heating-pressing means is suitable. Examples of the heating and pressing means include a combination of a heating roller and a pressing roller, a combination of a heating roller, a pressing roller, and an endless belt.
The fixing device includes a heating body including a heating element, a film in contact with the heating body, and a pressure member in pressure contact with the heating body through the film, and the film and the pressure member It is preferably a unit that heats and fixes a recording medium on which an unfixed image is formed. The heating in the heating and pressing means is usually preferably 80 ° C to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and can be suitably performed by a neutralization unit.
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrostatic latent image carrier. Preferably mentioned.

The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier and can be suitably performed by a cleaning unit.
The cleaning means is not particularly limited, and may be appropriately selected from known cleaners as long as the toner remaining on the electrostatic latent image carrier can be removed. For example, a magnetic brush cleaner Suitable examples include electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

The recycling step is a step of recycling the toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit. There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.
The control step is a step of controlling each step, and each step can be suitably performed by a control means.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

  FIG. 6 shows a first example of the image forming apparatus of the present invention. The image forming apparatus 100A includes a photosensitive drum 10, a charging roller 20, an exposure device (not shown), a developing device 40, an intermediate transfer belt 50, a cleaning device 60 having a cleaning blade, and a static elimination lamp 70. Prepare.

  The intermediate transfer belt 50 is an endless belt stretched by three rollers 51 arranged on the inner side, and can move in the direction of the arrow in the figure. A part of the three rollers 51 also functions as a transfer bias roller that can apply a transfer bias (primary transfer bias) to the intermediate transfer belt 50. Further, a cleaning device 90 having a cleaning blade is disposed in the vicinity of the intermediate transfer belt 50. Further, a transfer roller 80 capable of applying a transfer bias (secondary transfer bias) for transferring the toner image to the transfer paper 95 is disposed opposite to the intermediate transfer belt 50. Further, around the intermediate transfer belt 50, a corona charging device 58 for applying a charge to the toner image transferred to the intermediate transfer belt 50 is connected to the photosensitive drum 10 with respect to the rotation direction of the intermediate transfer belt 50. It is disposed between the contact portion of the intermediate transfer belt 50 and the contact portion of the intermediate transfer belt 50 and the transfer paper 95.

  The developing device 40 includes a developing belt 41 and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C provided around the developing belt 41. Each color developing unit 45 includes a developer container 42, a developer supply roller 43, and a developing roller (developer carrier) 44. The developing belt 41 is an endless belt stretched by a plurality of belt rollers, and can move in the direction of the arrow in the figure. Further, a part of the developing belt 41 is in contact with the photosensitive drum 10.

  Next, a method for forming an image using the image forming apparatus 100A will be described. First, the charging roller 20 is used to uniformly charge the surface of the photosensitive drum 10, and then the exposure light L is exposed to the photosensitive drum 10 using an exposure device (not shown) to form an electrostatic latent image. Form. Next, the electrostatic latent image formed on the photosensitive drum 10 is developed with the toner supplied from the developing device 40 to form a toner image. Further, after the toner image formed on the photosensitive drum 10 is transferred (primary transfer) onto the intermediate transfer belt 50 by the transfer bias applied from the roller 51, the transfer bias applied from the transfer roller 80 is used. Then, it is transferred (secondary transfer) onto the transfer paper 95. On the other hand, the photosensitive drum 10 on which the toner image is transferred to the intermediate transfer belt 50 is discharged by the discharging lamp 70 after the toner remaining on the surface is removed by the cleaning device 60.

  FIG. 7 shows a second example of the image forming apparatus used in the present invention. In the image forming apparatus 100B, the black developing unit 45K, the yellow developing unit 45Y, the magenta developing unit 45M, and the cyan developing unit 45C are arranged directly facing each other around the photosensitive drum 10 without providing the developing belt 41. Other than that, the configuration is the same as that of the image forming apparatus 100A.

FIG. 8 shows a third example of the image forming apparatus used in the present invention. The image forming apparatus 100 </ b> C is a tandem type color image forming apparatus, and includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.
The intermediate transfer belt 50 provided at the center of the copying apparatus main body 150 is an endless belt stretched around three rollers 14, 15 and 16, and can move in the direction of the arrow in the figure. In the vicinity of the roller 15, a cleaning device 17 having a cleaning blade for removing toner remaining on the intermediate transfer belt 50 on which the toner image has been transferred onto the recording paper is disposed. The image forming units 120Y, 120C, 120M, and 120K for yellow, cyan, magenta, and black are juxtaposed along the conveyance direction while facing the intermediate transfer belt 50 stretched by the rollers 14 and 15. An exposure device 21 is disposed in the vicinity of the image forming unit 120. Further, the secondary transfer belt 24 is disposed on the side of the intermediate transfer belt 50 opposite to the side on which the image forming unit 120 is disposed. The secondary transfer belt 24 is an endless belt stretched around a pair of rollers 23, and the recording paper and the intermediate transfer belt 50 conveyed on the secondary transfer belt 24 are between the rollers 16 and 23. Can touch. Further, in the vicinity of the secondary transfer belt 24, a fixing device 25 is provided with a fixing belt 26 that is an endless belt stretched between a pair of rollers, and a pressure roller 27 that is arranged to be pressed against the fixing belt 26. Is arranged. A sheet reversing device 28 for reversing the recording paper when an image is formed on both sides of the recording paper is disposed in the vicinity of the secondary transfer belt 24 and the fixing device 25.

  Next, a method for forming a full-color image using the image forming apparatus 100C will be described. First, a color document is set on the document table 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and a color document is set on the contact glass 32 of the scanner 300 to automatically convey the document. The device 400 is closed. When a start switch (not shown) is pressed, when an original is set on the automatic document feeder 400, the original is conveyed and moved onto the contact glass 32, and then the original is set on the contact glass 32. In this case, the scanner 300 is immediately driven, and the first traveling body 33 including the light source and the second traveling body 34 including the mirror travel. At this time, the reflected light from the original surface of the light irradiated from the first traveling body 33 is reflected by the second traveling body 34 and then received by the reading sensor 36 via the imaging lens 35, whereby the original is received. It is read and image information of black, yellow, magenta and cyan is obtained.

The image information for each color is transmitted to the image forming unit 120 for each color, and a toner image for each color is formed. As shown in FIG. 9, the image forming units 120 for each color each include a photosensitive drum 10, a charging roller 160 that uniformly charges the photosensitive drum 10, and image information for each color. An exposure device that exposes the exposure light L to form an electrostatic latent image of each color; a developing device 61 that develops the electrostatic latent image with a developer of each color to form a toner image of each color; A transfer roller 62 for transferring onto the transfer belt 50, a cleaning device 63 having a cleaning blade, and a static elimination lamp 64 are provided.
The toner images of the respective colors formed by the image forming units 120 of the respective colors are sequentially transferred (primary transfer) onto the intermediate transfer body 50 that is stretched and moved by the rollers 14, 15, and 16, and superimposed to form a composite toner image. It is formed.

  On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed recording paper from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143, and one sheet at a time by the separation roller 145. The paper is separated and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 to stop. Alternatively, the paper feed roller is rotated to feed out the recording paper on the manual feed tray 54, separated one by one by the separation roller 52, guided to the manual paper feed path 53, and abutted against the registration roller 49 and stopped. The registration roller 49 is generally used while being grounded, but may be used in a state where a bias is applied in order to remove paper dust from the recording paper. Next, by rotating the registration roller 49 in synchronization with the composite toner image formed on the intermediate transfer belt 50, the recording paper is sent between the intermediate transfer belt 50 and the secondary transfer belt 24, and the composite toner image is sent. The toner image is transferred onto the recording paper (secondary transfer). The toner remaining on the intermediate transfer belt 50 to which the composite toner image has been transferred is removed by the cleaning device 17.

  The recording paper on which the composite toner image has been transferred is conveyed by the secondary transfer belt 24 and then the composite toner image is fixed by the fixing device 25. Next, the conveyance path of the recording paper is switched by the switching claw 55, and the recording paper is discharged onto the paper discharge tray 57 by the discharge roller 56. Alternatively, the recording path of the recording paper is switched by the switching claw 55, reversed by the sheet reversing device 28, an image is similarly formed on the back side, and then discharged onto the discharge tray 57 by the discharge roller 56. .

  The image forming apparatus of the present invention can provide high-quality images over a long period of time.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples. In addition, unless otherwise indicated, the part in an Example represents a mass part, and% represents the mass%.

(Production Examples 1-12)
<Manufacture of external additives 1-12>
The production of the external additives 1 to 10 is performed by mixing primary particles of silica having various average particle diameters and a treatment agent with a spray dryer and firing them under the conditions shown in Table 1. After producing coalesced particles, a classifying apparatus was used to obtain a sharp particle size distribution. In addition, the external additives 11 to 12 were produced by subjecting the primary particles of silica having various average particle diameters to a hydrophobization treatment, but without the treatment with the treatment agent.
The treating agent was prepared by adding 0.1 part of a processing aid (water or 1% aqueous acetic acid solution) to 1 part of methyltrimethoxysilane. Table 1 shows the average particle diameter, shape, etc. of secondary particles produced by coalescing the primary particles.

<Various measurements>
For Db ₅₀ in the coalesced particles (secondary particles), the particle size of the coalesced particles was measured, and the particle size at which the cumulative value was 50% by number when the cumulative distribution was drawn from the small particle side was determined. Db ₁₀ was obtained by measuring the particle size of coalesced particles and obtaining a particle size with a cumulative value of 10% by number when a cumulative distribution was drawn from the small particle side.
The number average particle diameter (Dba) of the coalesced particles (secondary particles) is measured by measuring the longest length of aggregated particles (the length of the arrow shown in FIG. 2) (measured number of particles: 150), The average particle diameter (Da) of the primary particles of the coalesced particles is estimated based on the outer frame of the fused silica, and is the maximum length of all the images (the lengths of all arrows shown in FIG. 1). The average value was measured (measured number of particles: 150).
The particle diameter of each of these particles is measured by dispersing the coalesced particles in a suitable solvent (such as THF) and then removing the solvent on the substrate to dry the sample, using a field emission scanning electron microscope. (FE-SEM, acceleration voltage: 5 kV to 8 kV, observation magnification: 8,000 times to 10,000 times) was performed by measuring the particle diameter in the visual field.

<Manufacture of carrier A>
The following carrier materials were dispersed with a homomixer for 10 minutes to obtain a coating layer forming solution of acrylic resin and silicone resin containing alumina particles. Firing ferrite powder [(MgO) _1.8 (MnO) _49.5 (Fe ₂ O ₃ ) _48.0 : weight average particle diameter; 35 μm] as the core material so that the coating layer forming solution has a thickness of 0.15 μm on the surface of the core material The coated ferrite powder was obtained by applying and drying with a Spira coater (Okada Seiko Co., Ltd.). The obtained coated ferrite powder was fired in an electric furnace at 150 ° C. for 1 hour. After cooling, the ferrite powder bulk was crushed using a sieve having an aperture of 106 μm to obtain a carrier. In the film thickness measurement, since the coating layer covering the carrier surface can be observed by observing the cross section of the carrier with a transmission electron microscope, the average value of the thicknesses was taken as the thickness of the coating layer. Thus, carrier A having a weight average particle diameter of 35 μm was obtained.
[Raw material for Carrier A]
・ Acrylic resin solution (solid content 50%) 21.0 parts ・ Guanamine resin solution (solid content 70%) 6.4 parts ・ Alumina particles (0.3 μm, specific resistance 10 ¹⁴ Ω · cm) 7.6 parts Silicone resin solution (solid content 23%) 65.0 parts [SR2410, manufactured by Dow Corning Toray]
Aminosilane coupling agent (solid content: 100%) 1.0 part [SH6020, manufactured by Toray Dow Corning Co., Ltd.]
・ Toluene: 60.0 parts ・ Butyl cellosolve: 60.0 parts

<Evaluation of cracking or disintegration of external additives>
Using a rocking mill (manufactured by Seiwa Giken Co., Ltd.) for 50 g consisting of 0.5 g of each external additive 1-12 and 49.5 g of the carrier A, placed in a 50 mL bottle (manufactured by Nidec Rika Glass Co., Ltd.) The mixture was stirred at 67 Hz for 10 minutes. The stirred developer was diluted and dispersed in tetrahydrofuran (THF), and the external additive was separated on the supernatant liquid side, followed by observation with a field emission scanning electron microscope (FE-SEM). By the FE-SEM observation, the ratio (%) of the number of cracked or disintegrated particles in 1,000 particles of the external additive was determined. FIG. 4 shows a photograph of a measurement result in which the ratio of the number of cracked or disintegrated particles is 30% or less, and FIG. 5 shows a photograph of a measurement result in which the ratio of the number of cracked or disintegrated particles exceeds 30%. At the time of measurement, the particles existing alone as shown by reference numeral 2 in FIG. 3 and the particles existing alone as shown in a black frame in FIGS. The ratio was counted by counting as “cracked or disintegrated particles”.

(Production Example 13)
<Manufacture of crystalline polyester resin 1>
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introducing tube, 202 parts by mass (1.00 mol) of sebacic acid, 154 parts by mass (1.30 mol) of 1,6-hexanediol, and tetrabutoxy titanate as a condensation catalyst 0.5 part by mass was added, and the reaction was carried out for 8 hours at 180 ° C. while distilling off the water produced under a nitrogen stream. Next, while gradually raising the temperature to 220 ° C., the reaction was carried out for 4 hours while distilling off the water and 1,6-hexanediol produced under a nitrogen stream, and the Mw was about 15 under a reduced pressure of 5 to 20 mmHg. The reaction was continued until it reached 1,000, and [Crystalline Polyester Resin 1] was obtained. The obtained [Crystalline Polyester Resin 1] had a Mw of 14,000 and a melting point of 66 ° C.

(Production Example 14)
<Production of Amorphous Polyester Resin 1 (Unmodified Polyester Resin)>
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen insertion tube, 222 parts by mass of bisphenol A EO 2 mol adduct, 129 parts by mass of bisphenol A PO 2 mol adduct, 150 parts by mass of terephthalic acid, 15 parts by mass of adipic acid, and tetrabutoxy 0.5 parts by mass of titanate was added, and the reaction was carried out for 8 hours while distilling off the water produced at 230 ° C. and normal pressure under a nitrogen stream. Next, the reaction was carried out under reduced pressure of 5 to 20 mmHg. When the acid value reached 2, it was cooled to 180 ° C., 35 parts by mass of trimellitic anhydride was added, and the reaction was carried out at normal pressure for 3 hours. Polyester resin 1] was obtained. The obtained [Non-crystalline polyester resin 1] had Mw of 6,000 and Tg of 54 ° C.

(Production Example 15)
<Manufacture of non-crystalline polyester resin 2 (unmodified polyester resin)>
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen insertion tube, 212 parts by mass of bisphenol A EO 2 mol adduct, 116 parts by mass of bisphenol A PO 2 mol adduct, 166 parts by mass of terephthalic acid, and 0.5 parts by mass of tetrabutoxy titanate The reaction was carried out for 8 hours while distilling off the water produced at 230 ° C. and normal pressure under a nitrogen stream. Subsequently, it was made to react under the reduced pressure of 5-20 mmHg, and it reacted until Mw reached about 15,000, and [Amorphous polyester resin 2] was obtained. The obtained [Non-crystalline polyester resin 2] had a Mw of 14,000 and a Tg of 60 ° C.

(Production Example 16)
<Manufacture of non-crystalline polyester resin 3 (unmodified polyester resin)>
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen insertion tube, 204 parts by mass of bisphenol A EO 2 mol adduct, 106 parts by mass of bisphenol A PO 2 mol adduct, 166 parts by mass of terephthalic acid, and 0.5 parts by mass of tetrabutoxy titanate The reaction was carried out for 8 hours while distilling off the water produced at 230 ° C. and normal pressure under a nitrogen stream. Subsequently, it was made to react under the reduced pressure of 5-20 mmHg, and it reacted until Mw reached about 40,000, and [Amorphous polyester resin 3] was obtained. The obtained [Non-crystalline polyester resin 3] had Mw of 38,000 and Tg of 62 ° C.

(Production Example 17)
<Manufacture of polyester prepolymer>
720 parts by mass of bisphenol A EO 2 mol adduct, 90 parts by mass of bisphenol A PO2 mol adduct, 290 parts by mass of terephthalic acid, and 1 part by mass of tetrabutoxy titanate are placed in a reaction vessel equipped with a condenser, a stirrer and a nitrogen insertion tube. The reaction was carried out for 8 hours while distilling off the water produced at 230 ° C. and normal pressure under a nitrogen stream. Subsequently, it was made to react under reduced pressure of 10-15 mmHg for 7 hours, and [Intermediate polyester 1] was obtained. [Intermediate polyester 1] was Mn3,200 and Mw9,300.
Next, 400 parts by mass of the obtained [intermediate polyester 1], 95 parts by mass of isophorone diisocyanate, and 500 parts by mass of ethyl acetate were placed in a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen insertion tube. Was reacted at 80 ° C. for 8 hours to obtain a 50% by mass ethyl acetate solution of [polyester prepolymer 1] having an isocyanate group at the terminal. [Polyester prepolymer 1] had a free isocyanate mass% of 1.47%.

(Production Example 18)
<Production of graft polymer>
In a reaction vessel equipped with a stir bar and a thermometer, 480 parts by mass of xylene and 100 parts by mass of low molecular weight polyethylene (Sanwax LEL-400 manufactured by Sanyo Chemical Industries, Ltd .: softening point 128 ° C.) are sufficiently dissolved and purged with nitrogen. After that, a mixed solution of 740 parts by mass of styrene, 100 parts by mass of acrylonitrile, 60 parts by mass of butyl acrylate, 36 parts by mass of di-t-butylperoxyhexahydroterephthalate, and 100 parts by mass of xylene was dropped at 170 ° C. for 3 hours. The polymer was polymerized and held at this temperature for 30 minutes. Next, the solvent was removed to synthesize [graft polymer]. The obtained [graft polymer] had Mw of 24,000 and Tg of 67 ° C.

(Production Example 19)
<Manufacture of toner base 1 (ester elongation method)>
-Preparation of release agent dispersion 1-
50 parts by weight of paraffin wax (HNP-9, manufactured by Nippon Seiki Co., Ltd., melting point 75 ° C.), 30 parts by weight of [graft polymer], and 420 parts of ethyl acetate are placed in a container equipped with a stirring bar and a thermometer. The temperature was raised to 80 ° C., kept at 80 ° C. for 5 hours, cooled to 30 ° C. in 1 hour, and using a bead mill (Ultra Visco Mill, manufactured by IMEX), the liquid feeding speed was 1 kg / hr, and the disk peripheral speed. 6 m / sec, 80% by volume of 0.5 mm zirconia beads were filled, and dispersion was carried out under the conditions of 3 passes to obtain [Partitioner Dispersion Liquid 1].

-Production of master batch 1-
Non-crystalline polyester resin 1 100 parts by mass Carbon black (Printex 35, manufactured by Degussa) 100 parts by mass (DBP oil absorption: 42 mL / 100 g, pH: 9.5)
-Ion exchange water 50 mass parts Said raw material was mixed using the Henschel mixer (made by Mitsui Mining Co., Ltd.). The obtained mixture was kneaded using two rolls. The kneading temperature started kneading from 90 ° C., and then gradually cooled to 50 ° C. The obtained kneaded material was pulverized with a pulverizer (manufactured by Hosokawa Micron Corporation) to prepare [Masterbatch 1].

-Production of oil phase 1-
In a container equipped with a thermometer and a stirrer, 107 parts by weight of [Non-crystalline polyester resin 1], 75 parts by weight of [Releasing agent dispersion 1], 18 parts by weight of [Masterbatch 1], 73 parts by weight of ethyl acetate And pre-dispersed with a stirrer, and then stirred with a TK homomixer (manufactured by Tokushu Kika Co., Ltd.) at a rotational speed of 5,000 rpm to uniformly dissolve and disperse to obtain [oil phase 1]. It was.

―Manufacture of aqueous dispersion of resin fine particles―
In a reaction vessel equipped with a stirrer and a thermometer, 600 parts by mass of water, 120 parts by mass of styrene, 100 parts by mass of methacrylic acid, 45 parts by mass of butyl acrylate, sodium salt of alkylallylsulfosuccinate (Eleminol JS-2, Sanyo Chemical Industries) When 10 parts by mass and 1 part by mass of ammonium persulfate were charged and stirred at 400 rpm for 20 minutes, a white emulsion was obtained. This emulsion was heated to raise the temperature in the system to 75 ° C. and reacted for 6 hours. Further, 30 parts by mass of a 1% ammonium persulfate aqueous solution was added and aged at 75 ° C. for 6 hours to obtain [Aqueous dispersion of resin fine particles]. The volume average particle diameter of the particles contained in this [resin fine particle aqueous dispersion] was 60 nm, the weight average molecular weight of the resin component was 140,000, and Tg was 73 ° C.

-Preparation of aqueous phase 1-
990 parts by weight of water, 83 parts by weight of an aqueous dispersion of resin fine particles, 37 parts by weight of a 48.5% by weight aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries, Ltd.), and 90 ethyl acetate Mass parts were mixed and stirred to obtain [Aqueous Phase 1].

―Emulsification or dispersion―
To 273 parts by mass of [Oil Phase 1], 45 parts by mass of an ethyl acetate solution of [Polyester Prepolymer 1] and 3 parts by mass of a 50% by mass ethyl acetate solution of isophoronediamine were added, and a TK homomixer (specialized mechanized stock) was added. The product was stirred at a rotational speed of 5,000 rpm and uniformly dissolved and dispersed to obtain [Oil Phase 1 ′]. Then, 400 parts by mass of [Aqueous Phase 1] is put in another container in which a stirrer and a thermometer are set, and stirred at 13,000 rpm with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) Oil phase 1 ′] was added and emulsified for 1 minute to obtain [Emulsified slurry 1].

-Solvent removal-Cleaning-Drying-
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and the solvent was removed at 30 ° C. for 8 hours to obtain [Slurry 1]. The obtained [Slurry 1] was filtered under reduced pressure, and then the following washing treatment was performed.
(1) 100 parts by mass of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (5 minutes at a rotation speed of 6,000 rpm), and then filtered.
(2) 100 parts by mass of a 10% by mass aqueous sodium hydroxide solution was added to the filter cake of (1) and mixed with a TK homomixer (rotation speed: 6,000 rpm for 10 minutes), followed by filtration under reduced pressure.
(3) 100 parts by mass of 10 mass% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (5 minutes at a rotation speed of 6,000 rpm), and then filtered.
(4) Add 300 parts by mass of ion-exchanged water to the filter cake of (3), mix with a TK homomixer (5 minutes at 6,000 rpm), and then filter twice to obtain filter cake 1 It was.
The obtained filter cake 1 was dried at 45 ° C. for 48 hours with a circulating dryer. Thereafter, the toner base 1 was prepared by sieving with a mesh of 75 μm.

(Production Example 20)
<Manufacture of toner base 2 (ester elongation method)>
-Preparation of crystalline polyester resin dispersion 1-
100 parts by weight of [Crystalline Polyester Resin 1] and 400 parts of ethyl acetate are put in a container in which a stir bar and a thermometer are set, and heated and dissolved at 75 ° C. with stirring. Using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), dispersion was performed for 5 hours under the conditions of a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 80% by volume of 0.5 mm zirconia beads. A polyester resin dispersion 1] was obtained.

-Production of oil phase 2-
In a container equipped with a thermometer and a stirrer, 93 parts by mass of [Amorphous Polyester Resin 1], 68 parts by mass of [Crystalline Polyester Resin Dispersion 1], 75 parts by mass of [Releasing Agent Dispersion 1], [Master Batch 1] 18 parts by mass and 19 parts by mass of ethyl acetate were added and pre-dispersed with a stirrer, and then stirred with a TK homomixer (made by Tokushu Kika Co., Ltd.) at a rotation speed of 5,000 rpm, and uniform. Was dissolved and dispersed in [Oil Phase 2].

―Emulsification or dispersion―
To 273 parts by mass of [Oil Phase 2], 45 parts by mass of an ethyl acetate solution of [Polyester Prepolymer 1] and 3 parts by mass of 50% by mass of isophoronediamine in ethyl acetate were added, and a TK homomixer (specialized mechanized stock) was added. The product was stirred at a rotational speed of 5,000 rpm and uniformly dissolved and dispersed to obtain [Oil Phase 2 ′]. Then, 400 parts by mass of [Aqueous Phase 1] is put in another container in which a stirrer and a thermometer are set, and stirred at 13,000 rpm with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) Oil phase 2 ′] was added and emulsified for 1 minute to obtain [Emulsified slurry 2].

-Solvent removal-Cleaning-Drying-
[Emulsion slurry 2] was subjected to solvent removal, washing, drying, and air sieving under the same conditions as in [Emulsion slurry 1] to prepare toner base 2.

(Production Example 21)
<Manufacture of toner base 3 (dissolution suspension method)>
-Preparation of oil phase 3-
In a container equipped with a thermometer and a stirrer, 107 parts by mass of [Non-crystalline polyester resin 1], 23 parts by mass of [Non-crystalline polyester resin 3], 75 parts by mass of [Releasing agent dispersion 1], [Masterbatch 1] Put 18 parts by mass and 97 parts by mass of ethyl acetate, pre-disperse with a stirrer, and then stir at a rotational speed of 5,000 rpm with a TK type homomixer (manufactured by Tokushu Kika Co., Ltd.). [Oil phase 3] was obtained by dissolving and dispersing.

―Emulsification or dispersion―
Put 400 parts by mass of [Aqueous Phase 1] in another container with a stirrer and thermometer, and stir at 13,000 rpm with a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.). 3] was added and emulsified for 1 minute to obtain [Emulsified slurry 3].

-Solvent removal-Cleaning-Drying-
[Emulsion slurry 3] was subjected to solvent removal, washing, drying, and air sieving under the same conditions as in [Emulsion slurry 1] to prepare toner base 3.

(Production Example 22)
<Manufacture of toner base 4 (dissolution suspension method)>
-Production of oil phase 4-
In a container equipped with a thermometer and a stirrer, 93 parts by mass of [Non-crystalline polyester resin 1], 23 parts by mass of [Non-crystalline polyester resin 3], 68 parts by mass of [Crystalline polyester resin dispersion 1], Mold Dispersion Liquid 1] 75 parts by mass, [Masterbatch 1] 18 parts by mass, and 43 parts by mass of ethyl acetate were added and pre-dispersed with a stirrer, and then TK homomixer (manufactured by Tokushu Kika Co., Ltd.) The mixture was stirred at 5,000 rpm and uniformly dissolved and dispersed to obtain [Oil Phase 4].

―Emulsification or dispersion―
Put 400 parts by mass of [Aqueous Phase 1] in another container with a stirrer and thermometer, and stir at 13,000 rpm with a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.). 4] was added and emulsified for 1 minute to obtain [Emulsified slurry 4].

-Solvent removal-Cleaning-Drying-
[Emulsion slurry 4] was subjected to solvent removal, washing, drying, and air sieving under the same conditions as in [Emulsion slurry 1] to prepare toner base 4.

(Production Example 23)
<Manufacture of toner base 5 (emulsion aggregation method)>
-Preparation of amorphous polyester resin dispersion 2-
[Amorphous polyester resin 2] 60 parts by mass of ethyl acetate was added to 60 parts by mass and dissolved. Next, 120 parts by weight of water, 2 parts by weight of an anionic surfactant (Neogen R, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and 2.4 parts by weight of a 2% by weight aqueous sodium hydroxide solution were mixed in [Aqueous phase] 120 parts by mass of the resin solution was added and emulsified using a homogenizer (manufactured by IKA, Ultra Tarrax T50), and then emulsified with a Manton Gorin high-pressure homogenizer (manufactured by Gorin) to obtain an [emulsified slurry].
Next, the [emulsified slurry] was put into a container in which a stirrer and a thermometer were set, and the solvent was removed at 30 ° C. for 4 hours to obtain [Amorphous polyester resin dispersion 2]. It was 0.15 micrometer when the volume average particle diameter of the particle | grains in the obtained [amorphous polyester resin dispersion liquid 2] was measured with the particle size distribution measuring apparatus (LA-920, Horiba, Ltd. make).

-Preparation of amorphous polyester resin dispersion 3-
In the production of [Non-crystalline polyester resin dispersion liquid 2], [Non-crystalline polyester resin dispersion liquid 3] was similarly obtained except that [Non-crystalline polyester resin 2] was replaced with [Non-crystalline polyester resin 3]. ] Was obtained. It was 0.16 micrometer when the volume average particle diameter of the particle | grains in the obtained [amorphous polyester resin dispersion liquid 3] was measured with the particle size distribution measuring apparatus (LA-920, Horiba, Ltd. make).

-Preparation of release agent dispersion 2-
25 parts by mass of paraffin wax (HNP-9, manufactured by Nippon Seiki Co., Ltd., melting point 75 ° C.), 1 part by mass of an anionic surfactant (Neogen R, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 200 parts by mass of water are mixed, and 90 ° C. And melted. Next, this melt was emulsified with a homogenizer (IKA, Ultra Tarrax T50) and then emulsified with a Menton Gorin high-pressure homogenizer (Gorin) to obtain [Releasing Agent Dispersion 2].

-Preparation of Colorant Dispersion 1-
Carbon black (Printtex 35, manufactured by Degussa) 20 parts by mass, anionic surfactant (Neogen R, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by mass, and water 80 parts by mass are mixed together, and a TK homomixer (special machine) And [Colorant Dispersion 1] was obtained.

―Agglomeration―
In a container equipped with a thermometer and a stirrer, 235 parts by mass of [Amorphous polyester resin dispersion 2], 57 parts by mass of [Amorphous polyester resin dispersion 3], and 45 parts by mass of [Releasing agent dispersion 2] [Colorant dispersion 1] 26 parts by mass and 600 parts by mass of water were added and stirred at 30 ° C. for 30 minutes. The dispersion was adjusted to pH 10 by adding a 2% by weight aqueous sodium hydroxide solution. Next, the dispersion was heated to 45 ° C. while gradually dropping 50 parts by mass of a 5% by mass magnesium chloride aqueous solution while stirring at 5000 rpm with a homogenizer (manufactured by IKA, Ultra Turrax T50). The agglomerated particles were maintained at 45 ° C. until the volume average particle diameter grew to 5.3 μm. While heating at 90 ° C. while maintaining pH 9 by adding a 2% by weight aqueous sodium hydroxide solution to this, holding in this state for 2 hours, cooling to 20 ° C. at 1 ° C./min, [Slurry 5] Obtained.

-Solvent removal-Cleaning-Drying-
[Slurry 5] was washed, dried, and air sieved under the same conditions as in [Slurry 1] to prepare toner base 5.

(Production Example 24)
<Manufacture of toner base 6 (emulsion aggregation method)>
-Preparation of crystalline polyester resin dispersion 2-
[Crystalline Polyester Resin 1] 60 parts by mass of ethyl acetate was added to 60 parts by mass and mixed and stirred at 60 ° C. to dissolve. Next, 120 parts by weight of water, 2 parts by weight of an anionic surfactant (Neogen R, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and 2.4 parts by weight of a 2% by weight aqueous sodium hydroxide solution were mixed in [Aqueous phase] 120 parts by mass of the resin solution was added and emulsified using a homogenizer (manufactured by IKA, Ultra Turrax T50), and then emulsified with a Menton Gorin high-pressure homogenizer (manufactured by Gorin) to obtain [emulsified slurry].
Next, the [emulsified slurry] was put into a container in which a stirrer and a thermometer were set, and the solvent was removed at 60 ° C. for 4 hours to obtain [Crystalline polyester resin dispersion 2]. It was 0.17 micrometer when the volume average particle diameter of the particle | grains in the obtained [crystalline polyester resin dispersion liquid 2] was measured with the particle size distribution analyzer (LA-920, Horiba, Ltd. make).

―Agglomeration―
In a container equipped with a thermometer and a stirrer, 207 parts by mass of [Amorphous polyester resin dispersion 2], 57 parts by mass of [Amorphous polyester resin dispersion 3], 28 parts of [Crystalline polyester resin dispersion 2] Part, [release agent dispersion 2] 45 parts by mass, [colorant dispersion 1] 26 parts by mass and water 600 parts by mass were stirred at 30 ° C. for 30 minutes. The dispersion was adjusted to pH 10 by adding a 2% by weight aqueous sodium hydroxide solution. Next, the dispersion was heated to 45 ° C. while gradually dropping 50 parts by mass of a 5% by mass magnesium chloride aqueous solution while stirring at 5000 rpm with a homogenizer (manufactured by IKA, Ultra Turrax T50). The agglomerated particles were maintained at 45 ° C. until the volume average particle diameter grew to 5.3 μm. This was cooled to 20 ° C. to obtain [Slurry 6].

-Solvent removal-Cleaning-Drying-
[Slurry 6] was washed, dried, and air sieved under the same conditions as in [Slurry 1] to prepare a toner base 6.

(Production Example 25)
<Manufacture of toner base 7 (pulverization method)>
-Production of master batch 2-
Non-crystalline polyester resin 2 100 parts by mass Carbon black (Printex 35, manufactured by Degussa) 100 parts by mass (DBP oil absorption: 42 mL / 100 g, pH: 9.5)
-Ion exchange water 50 mass parts Said raw material was mixed using the Henschel mixer (made by Mitsui Mining Co., Ltd.). The obtained mixture was kneaded using two rolls. The kneading temperature started kneading from 90 ° C., and then gradually cooled to 50 ° C. The obtained kneaded material was pulverized with a pulverizer (manufactured by Hosokawa Micron Corporation) to prepare [Masterbatch 2].

-Melt kneading, grinding, classification-
[Amorphous polyester resin 2] 49 parts by mass, [Amorphous polyester resin 3] 40 parts by mass, 6 parts by mass of paraffin (HNP-9, Nippon Seiki Co., Ltd., melting point 75 ° C.), and [Masterbatch 2] 12 parts by mass was premixed at 1,500 rpm for 3 minutes using a Henschel mixer (Henschel 20B, manufactured by Mitsui Mining Co., Ltd.), and then with a uniaxial kneader (compact bus co-kneader, manufactured by Buss). Melting and kneading were performed under the conditions of a preset temperature (inlet part 90 ° C.), outlet part (60 ° C.), and feed amount (10 kg / Hr). The obtained kneaded product was rolled and cooled, and coarsely pulverized with a pulverizer (manufactured by Hosokawa Micron). Next, in a type I mill (made by Nippon Pneumatic Co., Ltd., IDS-2 type), using a flat collision plate, the air pressure (6.0 atm / cm ² ) and the feed amount (0.5 kg / hr) were set. The resultant was finely pulverized and further classified by a classifier (manufactured by Alpine, 132 MP) to obtain [Toner Base 7].

(Production Example 26)
<Manufacture of toner base 8 (pulverization method)>
-Melt kneading, grinding, classification-
[Amorphous Polyester Resin 2] 54 parts by mass, [Amorphous Polyester Resin 3] 27 parts by mass, [Crystalline Polyester Resin 1] 8 parts by mass, paraffin (HNP-9, manufactured by Nippon Seiki Co., Ltd., melting point 75 ° C. ) 6 parts by mass and 12 parts by mass of [Masterbatch 2] were premixed at 1,500 rpm for 3 minutes using a Henschel mixer (Henschel 20B, manufactured by Mitsui Mining Co., Ltd.), It was melted and kneaded under the conditions of a set temperature (inlet part 90 ° C.), outlet part (60 ° C.), and feed amount (10 kg / Hr) with Co Kneader (Buss). The obtained kneaded product was rolled and cooled, and coarsely pulverized with a pulverizer (manufactured by Hosokawa Micron). Next, in a type I mill (made by Nippon Pneumatic Co., Ltd., IDS-2 type), using a flat collision plate, the air pressure (6.0 atm / cm ² ) and the feed amount (0.5 kg / hr) were set. The resultant was finely pulverized and further classified by a classifier (manufactured by Alpine, 132MP) to obtain [Toner Base 8].

<Preparation of Toners 1 to 26>
According to Table 3, with respect to 100 parts by mass of the obtained [toner base 1] to [toner base 8], 2.0 parts by mass of any one of external additives 1 to 12 and a volume average particle diameter of 20 nm. Silica (trade name “H1303VP”, manufactured by Clariant) 2.0 parts by mass and titanium oxide (trade name “JMT-150IB”, manufactured by Teica) 0.6 part by mass were added to a Henschel mixer (Mitsui Mining Co., Ltd.). ) And passed through a sieve having a mesh size of 500 mesh to obtain toner 1 to toner 26.

<Manufacture of core particle 1>
MnCO ₃ , Mg (OH) ₂ , and Fe ₂ O ₃ powder were weighed and mixed to obtain a mixed powder. This mixed powder was calcined in a heating furnace at 900 ° C. for 3 hours in the air atmosphere, and the obtained calcined product was cooled and pulverized to obtain a powder having a particle diameter of approximately 1 μm. This powder was made into a slurry by adding 1 wt% of a dispersant together with water, and the slurry was supplied to a spray dryer and granulated to obtain a granulated product having an average particle size of about 40 μm. This granulated product was loaded into a firing furnace and fired at 1180 ° C. for 4 hours in a nitrogen atmosphere. The obtained fired product was pulverized with a pulverizer, and the particle size was adjusted by sieving to obtain [core particle 1] which is spherical ferrite particles having a volume average particle size of about 35 μm. SF-1 of this [core particle 1] was 135, SF-2 was 122, and Ra was 0.63 μm.

<Manufacture of core particle 2>
MnCO ₃ , Mg (OH) ₂ , and Fe ₂ O ₃ powder were weighed and mixed to obtain a mixed powder. This mixed powder was calcined in a heating furnace at 900 ° C. for 3 hours in the air atmosphere, and the obtained calcined product was cooled and pulverized to obtain a powder having a particle diameter of approximately 1 μm. This powder was made into a slurry by adding 1 wt% of a dispersant together with water, and the slurry was supplied to a spray dryer and granulated to obtain a granulated product having an average particle size of about 40 μm. This granulated product was loaded into a firing furnace and fired at 1300 ° C. for 5 hours in a nitrogen atmosphere. The obtained fired product was pulverized with a pulverizer, and the particle size was adjusted by sieving to obtain [core particle 2] which is spherical ferrite particles having a volume average particle size of about 35 μm. The [core particle 2] had SF-1 of 125, SF-2 of 119, and Ra of 0.45 μm.

<Manufacture of core particle 3>
MnCO ₃ , Mg (OH) ₂ , Fe ₂ O ₃ , and SrCO ₃ powder were weighed and mixed to obtain a mixed powder. This mixed powder was calcined in a heating furnace at 850 ° C. for 1 hour in the air atmosphere, and the obtained calcined product was cooled and pulverized to obtain a powder having a particle size of 3 μm or less. This powder was made into a slurry by adding 1 wt% dispersant together with water, and the slurry was supplied to a spray dryer and granulated to obtain a granulated product having a volume average particle size of about 40 μm. This granulated product was loaded into a firing furnace and fired at 1120 ° C. for 4 hours in a nitrogen atmosphere. The obtained fired product was pulverized with a pulverizer, and the particle size was adjusted by sieving to obtain [core particle 3], which is spherical ferrite particles having a volume average particle size of about 35 μm. SF of the [core particle 3] was 145, SF-2 was 155, and Ra was 0.85 μm.

<Manufacture of conductive inorganic fine particles 1>
100 g of aluminum oxide (AKP-30 manufactured by Sumitomo Chemical Co., Ltd.) was dispersed in 1 L of water to form a suspension, and this liquid was heated to 70 ° C. A solution prepared by dissolving 11.6 g of stannic chloride in 1 L of 2N hydrochloric acid and 12 mass% aqueous ammonia were added dropwise to this suspension over 40 minutes so that the pH of the suspension was 7-8. Subsequently, a solution obtained by dissolving 36.7 g of indium chloride and 5.4 g of stannic chloride in 450 mL of 2N hydrochloric acid and 12% by mass aqueous ammonia were added dropwise over 1 hour so that the pH of the suspension was 7-8. After dropping, the cake obtained by filtering and washing the suspension was dried at 110 ° C. Next, this dry powder was treated in a nitrogen stream at 500 ° C. for 1 hour to obtain [Conductive inorganic fine particles 1]. The obtained [Conductive inorganic fine particles 1] had a number average particle diameter of 300 nm and a volume resistivity of 4 Ω · cm.

<Production of non-conductive inorganic fine particles 1>
100 g of aluminum oxide (AKP-30 manufactured by Sumitomo Chemical Co., Ltd.) was dispersed in 1 L of water to form a suspension, and this liquid was heated to 70 ° C. To this suspension, a solution prepared by dissolving 10 g of stannic chloride and 0.30 g of phosphorus pentoxide in 100 mL of 2N hydrochloric acid and 12% by mass aqueous ammonia over 12 minutes so that the pH of the suspension is 7-8. It was dripped. After dropping, the cake obtained by filtering and washing the suspension was dried at 110 ° C. Next, this dry powder was treated in a nitrogen stream at 500 ° C. for 1 hour to obtain [Non-conductive inorganic fine particles 1]. The obtained [Nonconductive inorganic fine particles 1] had a number average particle diameter of 300 nm and a volume resistivity of 1200 Ω · cm.

<Manufacture of coating resin 1>
300 g of toluene was charged into a flask equipped with a stirrer, and the temperature was raised to 90 ° C. under a nitrogen gas stream. Subsequently, 3-methacryloxypropyltris (trimethylsiloxy) silane 84. shown by CH ₂ = CMe—COO—C ₃ H ₆ —Si (OSiMe ₃ ) ₃ (wherein Me is a methyl group) is added. 4 g (200 mmol: Silaplane TM-0701T / manufactured by Chisso Corporation), 37.2 g (150 mmol) of 3-methacryloxypropyltrimethoxysilane, 65.0 g (650 mmol) of methyl methacrylate, and 2,2′-azobis-2 -A mixture of 0.58 g (3 mmol) of methylbutyronitrile was added dropwise over 1 hour. After completion of the addition, a solution prepared by dissolving 0.06 g (0.3 mmol) of 2,2′-azobis-2-methylbutyronitrile in 15 g of toluene was further added (2,2′-azobis-2-methylbutyro The total amount of nitrile 0.64 g = 3.3 mmol) was mixed at 90 to 100 ° C. for 3 hours and radical copolymerized to obtain [Coating Resin 1].
The obtained [Coating resin 1] was Mw 34,000. Next, this [Coating Resin 1] solution was diluted with toluene so that the nonvolatile content was 25% by mass. The thus obtained [Coating resin 1] solution had a viscosity of 8.7 mm ² / s and a specific gravity of 0.91.

<Preparation of carrier 1>
Methyl silicone resin (Mw 15,000, solid content 25% by mass) 26 parts by mass, acrylic resin (Hitaroid 3001, solid content 50% by mass, manufactured by Hitachi Chemical Co., Ltd.) 2.5 made from a bifunctional or trifunctional monomer Parts by mass, 5 parts by mass of benzoguanamine resin (My Coat 106, solid content 77% by mass, manufactured by Mitsui Cytec), 20 parts by mass of [conductive inorganic fine particles 1], titanium diisopropoxybis (ethylacetoacetate) TC as a catalyst -750 (manufactured by Matsumoto Fine Chemical Co., Ltd.) 2 parts by mass and 1.4 parts by mass of SH6020 (manufactured by Toray Silicone Co., Ltd.) as a silane coupling agent were diluted with toluene to obtain a resin solution having a solid content of 10% by mass. This resin solution was coated on 1000 parts by mass of [core particle 1] by a dipping method using a multi-function mixer mixer. At this time, the carrier core material temperature was set to 100 ° C., the resin solution was put into the mixing mixer, the mixing stirring blade was rotated until the coating solution evaporated, the coating / stirring / drying treatment was performed, and the carrier was taken out. The obtained carrier was baked in an electric furnace at 180 ° C./2 hours to obtain carrier 1. This carrier 1 had a work function of 4.0 eV, SF-2: 114, and a carrier bulk density of 2.42 g / cm ³ .

<Production of Carrier 2>
Methyl silicone resin (Mw 15,000, solid content 25% by mass) 26 parts by mass, acrylic resin (Hitaroid 3001, solid content 50% by mass, manufactured by Hitachi Chemical Co., Ltd.) 2.5 made from a bifunctional or trifunctional monomer Parts by mass, 5 parts by mass of benzoguanamine-based resin (My Coat 106, solid content 77% by mass, manufactured by Mitsui Cytec), 16.4 parts by mass of [conductive inorganic fine particles 1], titanium diisopropoxybis (ethyl acetoacetate as a catalyst) ) 2 parts by mass of TC-750 (manufactured by Matsumoto Fine Chemical Co., Ltd.) and 0.7 parts by mass of SH6020 (manufactured by Toray Silicone Co., Ltd.) as a silane coupling agent are diluted with toluene to obtain a resin solution having a solid content of 10% by mass. It was. This resin solution was coated on 1000 parts by mass of [Core Particle 2] by a dipping method using a multi-function mixer mixer. At this time, the carrier core material temperature was set to 100 ° C., the resin solution was put into the mixing mixer, the mixing stirring blade was rotated until the coating solution evaporated, the coating / stirring / drying treatment was performed, and the carrier was taken out. The obtained carrier was baked at 180 ° C./2 hours in an electric furnace to obtain carrier 2. This carrier 2 had a work function of 4.3 eV, SF-2: 111, and a carrier bulk density of 2.46 g / cm ³ .

<Preparation of carrier 3>
Methyl silicone resin (Mw 15,000, solid content 25% by mass) 26 parts by mass, acrylic resin (Hitaroid 3001, solid content 50% by mass, manufactured by Hitachi Chemical Co., Ltd.) 2.5 made from a bifunctional or trifunctional monomer Parts by mass, 5 parts by mass of benzoguanamine resin (My Coat 106, solid content 77% by mass, manufactured by Mitsui Cytec), 18 parts by mass of [conductive inorganic fine particles 1], titanium diisopropoxybis (ethylacetoacetate) TC as a catalyst -750 (made by Matsumoto Fine Chemical Co., Ltd.) 2 parts by mass and SH6020 (made by Toray Silicone Co., Ltd.) 0.2 parts by mass as a silane coupling agent were diluted with toluene to obtain a resin solution having a solid content of 10% by mass. This resin solution was coated on 1000 parts by mass of [Core Particle 2] by a dipping method using a multi-function mixer mixer. At this time, the carrier core material temperature was set to 100 ° C., the resin solution was put into the mixing mixer, the mixing stirring blade was rotated until the coating solution evaporated, the coating / stirring / drying treatment was performed, and the carrier was taken out. The obtained carrier was baked in an electric furnace at 180 ° C./2 hours to obtain carrier 3. The carrier 3 had a work function of 4.4 eV and SF-2: 112, and the carrier bulk density was 2.44 g / cm ³ .

<Preparation of carrier 4>
Methyl silicone resin (Mw 15,000, solid content 25% by mass) 12 parts by mass, [Coating resin 1] (solid content 25% by mass) 48 parts by mass, [Conductive inorganic] Fine particles 1] 38 parts by mass, 1 part by mass of titanium diisopropoxybis (ethylacetoacetate) TC-750 (manufactured by Matsumoto Fine Chemical Co.) as a catalyst, 1.8 parts by mass of SH6020 (manufactured by Toray Silicone Co., Ltd.) as a silane coupling agent Was diluted with toluene to obtain a resin solution having a solid content of 10% by mass. The resin solution was coated and dried on 1000 parts by mass of [core particle 3] using a fluidized bed coating apparatus while controlling the temperature in the fluidized tank at 70 ° C. The obtained carrier was baked in an electric furnace at 180 ° C./2 hours to obtain carrier 4. This carrier 4 had a work function of 4.0 eV, SF-2: 139, and a carrier bulk density of 2.14 g / cm ³ .

<Preparation of carrier 5>
Methyl silicone resin (Mw 15,000, solid content 25% by mass) 64 parts by mass, [conductive inorganic fine particles 1] 56 parts by mass, titanium diisopropoxy bis (ethylacetate) as a catalyst, prepared from a bifunctional or trifunctional monomer Acetate) TC-750 (manufactured by Matsumoto Fine Chemical Co., Ltd.) 6 parts by weight, SH6020 (manufactured by Toray Silicone Co., Ltd.) 1.8 parts by weight as a silane coupling agent was diluted with toluene to obtain a resin solution having a solid content of 10% by weight. Obtained. The resin solution was coated and dried on 1000 parts by mass of [core particle 1] using a fluidized bed coating apparatus while controlling the temperature in the fluidized tank at 70 ° C. The obtained carrier was baked in an electric furnace at 180 ° C./2 hours to obtain carrier 5. This carrier 5 had a work function of 4.0 eV, SF-2: 114, and a carrier bulk density of 2.42 g / cm ³ .

<Measurement method of carrier work function>
The work function Wc of the carrier was measured using a work function measuring device (manufactured by Riken Keiki Co., Ltd., surface analysis device AC-2) using a photoelectric effect. Specifically, a carrier is put into a concave portion of a sample measuring cell (having a shape having a concave portion having a diameter of 10 mm and a depth of 1 mm in the center of a stainless steel disk having a diameter of 13 mm and a height of 5 mm), and a knife edge is used. The surface was leveled. After fixing the sample measurement cell filled with the carrier on the specified position of the sample stage, the irradiation light quantity was set to 500 nW, the irradiation area was set to 4 mm square, and the measurement was performed under the conditions of the energy scanning range of 3.4 to 6.2 eV.

Examples 1-22, Comparative Examples 1-4
<Preparation of developers 1 to 26>
According to Table 3, 70 parts by mass of each of toner 1 to toner 26 and 930 parts by mass of each of carriers 1 to 5 were mixed at 81 rpm for 5 minutes by a tumbler mixer, and Examples 1 to 22 and Comparative Examples 1 to 2 were mixed. 4 developers 1-26 were prepared. Each developer was mixed as a replenishment developer so that the carrier concentration was 10% by mass to prepare a replenishment developer.

  Next, according to Table 3, the obtained developers 1 to 26 are obtained from any one of the surface materials of Al (Ws: 3.7 eV), SUS (Ws: 4.4 eV), and TiN (Ws: 4.7 eV). The developing device equipped with the developer carrying member is filled, and the initial stability with respect to the hysteresis phenomenon, the stability over time (medium speed machine), the stability over time with respect to the hysteresis phenomenon (high speed machine), and the low temperature fixing as follows. The sex was evaluated and a comprehensive judgment was made. The results are shown in Table 3.

<Initial stability against hysteresis and stability over time (medium speed machine)>
Each developer and replenishment developer prepared in a commercially available digital full-color printer (image MPC6000, A4 horizontal color 50 sheets / min, manufactured by Ricoh) is set, and a character chart (size of one character; 2 mm) with an image area of 8% 10kp sheets were printed, and then 200kp sheets were printed. Regarding the hysteresis phenomenon, after outputting 10 kp sheets and after outputting 200 kp sheets, the longitudinal band chart shown in FIG. 10 is printed, and the image part (first sleeve) (a) after the non-image part and the image after the non-image part The density difference of the part (second round of the sleeve) (b) is X-Rite 938 (manufactured by X-Rite), the average density difference of the center, rear, and front measurements is ΔID, and 10 kp sheets are output according to the following criteria After ΔID was evaluated as a history phenomenon (initial stability, medium speed machine), and after outputting 200 kp sheets, ΔID was evaluated as a history phenomenon (time stability, medium speed machine).
[Evaluation criteria]
A: Very good, B: Good, B: Acceptable, B: Unusable for practical use A: B, B, C: Passed and x: Fail.
A: 0.01 ≧ ΔID
○: 0.01 <ΔID ≦ 0.03
Δ: 0.03 <ΔID ≦ 0.06
×: 0.06 <ΔID

<Stability with time against hysteresis (high speed machine)>
Each developer and replenishment developer prepared in a commercially available digital full color printer (RICOH Pro C901, A4 horizontal color 90 sheets / min, manufactured by Ricoh) was set, and a character chart (size of one character; 8% image area) 200 kp sheets (about 2 mm × 2 mm) were printed. Regarding the hysteresis phenomenon, and after printing 200 kp sheets, the vertical band chart shown in FIG. 10 is printed, and the image part after the non-image part (first sleeve) (a) and the image part after the non-image part (second sleeve) ) The density difference of (b) is X-Rite 938 (manufactured by X-Rite), the average density difference of the three measurements at the center, rear, and front is ΔID, and ΔID is output as a hysteresis phenomenon after outputting 200 kp sheets according to the following criteria. The stability over time and the high-speed machine were evaluated.
[Evaluation criteria]
A: Very good, B: Good, B: Acceptable, B: Unusable for practical use A: B, B, C: Passed and x: Fail.
A: 0.01 ≧ ΔID
○: 0.01 <ΔID ≦ 0.03
Δ: 0.03 <ΔID ≦ 0.06
×: 0.06 <ΔID

<Low temperature fixability>
Copying on recording paper (type 6200, manufactured by Ricoh Co., Ltd.) using a device in which the fixing unit of an image forming apparatus (MF2200, manufactured by Ricoh Co., Ltd.) using a Teflon (registered trademark) roller as a fixing roller is modified. Tested. Specifically, the cold offset temperature (fixing lower limit temperature) was determined by changing the fixing temperature. The evaluation conditions for the minimum fixing temperature were a paper feed linear velocity of 120 mm / second to 150 mm / second, a surface pressure of 1.2 kgf / cm ² , and a nip width of 3 mm. Evaluation of low-temperature fixability was evaluated according to the following criteria. The lower the fixing minimum temperature, the better the low-temperature fixability.
[Evaluation criteria]
◎: Very good, ○: Good, Δ: Acceptable, ×: Unusable level for practical use ◎, ○, △ were accepted and x was rejected.
A: Lower limit fixing temperature is less than 120 ° C. O: Lower limit fixing temperature is 120 ° C. or more and less than 130 ° C. Δ: Lower limit fixing temperature is 130 ° C. or more and less than 140 ° C.

<Comprehensive judgment>
◎: Very good, ◎: Very good, ◯: Good, △: Acceptable, ×: Unusable level for practical use ◎◎, ◎, ○, △ were accepted and x was rejected.
◎◎: There are three or more ◎, and △, × None ◎: Two ◎, △, × None ○: Other △: Two or more △, ◎, × None ×: × One or more

  From Table 3, the developers of Examples 1 to 22 are compared with the developers of Comparative Examples 1 to 4, with respect to the initial stability against the hysteresis phenomenon, the stability over time, and the stability over time against the hysteresis phenomenon in the high speed machine. Good results were obtained.

10 Electrostatic latent image carrier (photosensitive drum)
10K Black electrostatic latent image carrier 10Y Yellow electrostatic latent image carrier 10M Magenta electrostatic latent image carrier 10C Cyan electrostatic latent image carrier 14 Support roller 15 Support roller 16 Support roller 17 Intermediate transfer cleaning device 18 Image forming means 20 Charging roller 21 Exposure device 22 Secondary transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure roller 28 Sheet reversing device 32 Contact glass 33 First traveling body 34 Second traveling body 35 Imaging lens 36 Reading sensor 40 Developing device 41 Developing belt 42K Developer container 42Y Developer container 42M Developer container 42C Developer container 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer Supply roller 44K Developing roller 44Y Developing roller 44M Developing row 44C Development roller 45K Black development unit 45Y Yellow development unit 45M Magenta development unit 45C Cyan development unit 49 Registration roller 50 Intermediate transfer belt 51 Roller 52 Separation roller 53 Manual feed path 54 Manual feed tray 55 Switching claw 56 Discharge roller 57 Discharge tray 58 Corona Charging device 60 Cleaning device 61 Developing device 62 Transfer roller 63 Photoconductor cleaning device 64 Static discharge lamp 70 Static discharge lamp 80 Transfer roller 90 Cleaning device 95 Transfer paper 100A, 100B, 100C Image forming device 120 Image forming unit 130 Document base 142 Paper feed roller 143 Paper bank 144 Paper cassette 145 Separation roller 146 Paper feed path 147 Transport roller 148 Paper feed path 150 Copying device main body 160 Charging device 200 Paper feed tray Le 300 Scanner 400 automatic document feeder (ADF)

Japanese Patent No. 3005081 Japanese Patent No. 3126433 Japanese Patent Laid-Open No. 11-065247

Claims (7)

In a developing device provided with a developer carrying member disposed opposite to an electrostatic latent image carrying member and carrying a developer for developing the electrostatic latent image formed on the electrostatic latent image carrying member and transporting the developer to a development region. ,
The developer includes a toner base containing at least a binder resin and a colorant, a toner containing an external additive, and a carrier.
As the external additive, containing coalescing particles formed by coalescing a plurality of primary particles,
The developing device, wherein a work function Wc of the carrier and a work function Ws of the developer carrier satisfy the relationship of the following formula (1).
The developing device according to claim 1, wherein a particle size distribution index of the coalesced particles is represented by the following formula (2).
(In the formula (2), Db ₅₀ is the coalescence when the particle size (nm) of the coalesced particles is on the horizontal axis and the cumulative value (number%) of the coalesced particles is on the vertical axis. When the cumulative distribution of particles is drawn from the small particle side, it represents the particle size of the coalesced particles with the cumulative value of 50% by number, and Db ₁₀ represents the coalesced particles with the cumulative value of 10% by number. Represents the particle size of The developing device according to claim 1, wherein the coalesced particles satisfy the following formula (3).
(In the above formula (3), Nx represents the number of cracked or disintegrated particles in 1,000 of the coalesced particles. Note that the number of cracked or disintegrated particles in 1,000 of the particles. Was stirred with a rocking mill (SEIWAGIKEN) at 67 Hz for 10 minutes against 0.5 g of the coalesced particles and 49.5 g of the carrier in a 50 mL bottle, and then observed with a scanning electron microscope. select.)   The developing device according to claim 1, wherein the coalescing particles have a number average particle diameter of 80 nm to 200 nm.   The developing device according to claim 1, wherein the binder resin contains at least a crystalline polyester resin. The carrier has magnetic core particles and a coating layer covering the core particles, the shape factor SF-2 is 115 to 150, and the bulk density is 1.80 to 2.40 g / cm. ³ ,
The shape factor SF-2 of the core particles is 120 to 160, and the arithmetic average surface roughness Ra of the core particles is 0.5 to 1.0 μm.
6. The coating layer according to claim 1, wherein the coating layer contains a resin and inorganic fine particles, and the inorganic fine particles are contained in a proportion of 50 to 500 parts by mass with respect to 100 parts by mass of the resin. The developing device described. An electrostatic latent image carrier, charging means for charging the surface of the electrostatic latent image carrier, exposure means for exposing the charged surface of the electrostatic latent image carrier to form an electrostatic latent image, and Developing means for developing an electrostatic latent image with toner to form a visible image, transferring means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium An image forming apparatus having at least
An image forming apparatus, wherein the developing unit is the developing device according to claim 1.